[Samsung Galaxy S7 Edge (Exynos) ROMs, Kernels, Rec] germania:
Following up, this appears to be a relevant snippet of logcat --

07-25 21:10:15.911 3408 3408 D BluetoothManagerService: BluetoothServiceConnection, disconnected: com.android.bluetooth.btservice.AdapterService
07-25 21:10:15.911 3408 3442 E BluetoothManagerService: MESSAGE_BLUETOOTH_SERVICE_DISCONNECTED(1)
07-25 21:10:15.911 3408 3442 D BluetoothManagerService: Broadcasting onBluetoothServiceDown() to 5 receivers.
07-25 21:10:15.912 3408 3442 D BluetoothAdapter: onBluetoothServiceDown: Sending callbacks to 0 clients
07-25 21:10:15.912 3408 3442 D BluetoothAdapter: onBluetoothServiceDown: Finished sending callbacks to registered clients
07-25 21:10:15.912 3566 3578 D BluetoothAdapter: onBluetoothServiceDown: Sending callbacks to 0 clients
07-25 21:10:15.912 3566 3578 D BluetoothAdapter: onBluetoothServiceDown: Finished sending callbacks to registered clients
07-25 21:10:15.912 3814 3828 D BluetoothAdapter: onBluetoothServiceDown: Sending callbacks to 0 clients
07-25 21:10:15.912 3814 3828 D BluetoothAdapter: onBluetoothServiceDown: Finished sending callbacks to registered clients
07-25 21:10:15.912 4228 4658 D BluetoothAdapter: onBluetoothServiceDown: Sending callbacks to 0 clients
07-25 21:10:15.912 4228 4658 D BluetoothAdapter: onBluetoothServiceDown: Finished sending callbacks to registered clients
07-25 21:10:15.913 4134 5608 D BluetoothAdapter: onBluetoothServiceDown: Sending callbacks to 0 clients
07-25 21:10:15.913 4134 5608 D BluetoothAdapter: onBluetoothServiceDown: Finished sending callbacks to registered clients
07-25 21:10:15.913 3408 5967 I ActivityManager: Process com.android.bluetooth (pid 6080) has died
07-25 21:10:15.913 3408 5967 D ActivityManager: cleanUpApplicationRecord -- 6080
07-25 21:10:15.913 3408 5967 W ActivityManager: Scheduling restart of crashed service com.android.bluetooth/.gatt.GattService in 1000ms
07-25 21:10:15.914 3408 5967 W ActivityManager: Scheduling restart of crashed service com.android.bluetooth/.btservice.AdapterService in 1000ms
07-25 21:10:16.111 3408 3442 D BluetoothManagerService: MESSAGE_RESTART_BLUETOOTH_SERVICE
07-25 21:10:16.125 3408 3442 I ActivityManager: Start proc 6251:com.android.bluetooth/1002 for service com.android.bluetooth/.btservice.AdapterService
07-25 21:10:16.209 3089 3523 D bauth_FPBAuthService: pcf : 0x1012
07-25 21:10:16.209 3089 3523 D bauth_FPBAuthService: thread id : 1, preenroll_flag : 0
07-25 21:10:16.209 3089 3523 D bauth_FPBAuthService: FPBAuthService, 6480
07-25 21:10:16.315 6225 6225 W art : Verification of void gen_binder.root.RootModule$Generated.b() took 193.919ms
07-25 21:10:16.390 6251 6251 E BluetoothVendorJni: register_com_android_bluetooth_btservice_vendor:
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName HeadsetService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding HeadsetService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName A2dpService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding A2dpService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName HidService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding HidService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName HealthService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding HealthService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName PanService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding PanService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName GattService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding GattService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: addA2dpProfile: isA2dpSinkEnabled = falseisHfpClientEnabled false serviceName BluetoothMapService
07-25 21:10:16.405 6251 6251 D AdapterServiceConfig: Adding BluetoothMapService
07-25 21:10:16.415 6251 6251 E BluetoothVendorJni: register_com_android_bluetooth_btservice_vendor:
07-25 21:10:16.428 6251 6251 D BluetoothAdapterService: onCreate()
07-25 21:10:16.430 6251 6251 I BluetoothVendorJni: classInitNative: succeeds
07-25 21:10:16.431 6251 6251 D BluetoothAdapterState: make() - Creating AdapterState
07-25 21:10:16.432 6251 6251 I bt_btif : init
07-25 21:10:16.432 6251 6267 I BluetoothAdapterState: Entering OffState
07-25 21:10:16.432 6251 6268 W bt_osi_thread: run_thread: thread id 6268, thread name stack_manager started
07-25 21:10:16.432 6251 6268 I bt_stack_manager: event_init_stack is initializing the stack
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initializing module "osi_module"
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initialized module "osi_module"
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initializing module "bt_utils_module"
07-25 21:10:16.433 6251 6268 I bt_utils: init_soc_type
07-25 21:10:16.433 6251 6268 I bt_utils: qcom.bluetooth.soc set to rome
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initialized module "bt_utils_module"
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initializing module "btif_config_module"
07-25 21:10:16.433 6251 6271 W bt_osi_thread: run_thread: thread id 6271, thread name alarm_default_ca started
07-25 21:10:16.433 6251 6272 W bt_osi_thread: run_thread: thread id 6272, thread name alarm_dispatcher started
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initialized module "btif_config_module"
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initializing module "interop_module"
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initialized module "interop_module"
07-25 21:10:16.433 6251 6268 I bt_core_module: module_init Initializing module "stack_config_module"
07-25 21:10:16.433 6251 6268 I bt_stack_config: init attempt to load stack conf from /etc/bluetooth/bt_stack.conf
07-25 21:10:16.434 6251 6268 I bt_core_module: module_init Initialized module "stack_config_module"
07-25 21:10:16.434 6251 6273 W bt_osi_thread: run_thread: thread id 6273, thread name bt_jni_workqueue started
07-25 21:10:16.434 6251 6268 I bt_stack_manager: event_init_stack finished
07-25 21:10:16.434 6251 6251 I bt_btif : get_profile_interface socket
07-25 21:10:16.435 6251 6273 D BluetoothAdapterProperties: Address is:88:83:22:0A:49:BA
07-25 21:10:16.436 6251 6251 I bt_btif : get_profile_interface sdp
07-25 21:10:16.437 3408 3408 D BluetoothManagerService: Bluetooth Adapter name changed to Samsung Galaxy S7 Edge
07-25 21:10:16.437 6251 6273 D BluetoothAdapterProperties: Name is: Samsung Galaxy S7 Edge
07-25 21:10:16.437 3408 3408 D BluetoothManagerService: Stored Bluetooth name: Samsung Galaxy S7 Edge
07-25 21:10:16.439 6251 6251 I bt_btif : get_profile_interface vendor
07-25 21:10:16.439 6251 6251 D BluetoothAdapterService: setAdapterService() - set to: null
07-25 21:10:16.439 6251 6251 D BluetoothAdapterService: onBind()
07-25 21:10:16.440 3408 3408 D BluetoothManagerService: BluetoothServiceConnection: com.android.bluetooth.btservice.AdapterService
07-25 21:10:16.440 3408 3442 D BluetoothManagerService: MESSAGE_BLUETOOTH_SERVICE_CONNECTED: 1
07-25 21:10:16.441 6251 6263 I bt_btif : config_hci_snoop_log
07-25 21:10:16.442 3408 3442 D BluetoothManagerService: Broadcasting onBluetoothServiceUp() to 6 receivers.
07-25 21:10:16.444 6251 6264 D BluetoothAdapterService: enable() - Enable called with quiet mode status = false
07-25 21:10:16.444 6251 6267 D BluetoothAdapterState: Current state: OFF, message: 0
07-25 21:10:16.444 6251 6267 D BluetoothAdapterProperties: Setting state to 14
07-25 21:10:16.444 6251 6267 I BluetoothAdapterState: Bluetooth adapter state changed: 10-> 14
07-25 21:10:16.445 6251 6267 D BluetoothAdapterService: updateAdapterState() - Broadcasting state to 1 receivers.
07-25 21:10:16.445 6251 6267 D BluetoothAdapterService: BleOnProcessStart()
07-25 21:10:16.445 6251 6267 D BluetoothAdapterService: BleOnProcessStart() - Make Bond State Machine
07-25 21:10:16.445 3408 3442 D BluetoothManagerService: MESSAGE_BLUETOOTH_STATE_CHANGE: OFF > BLE_TURNING_ON
07-25 21:10:16.445 3408 3442 D BluetoothManagerService: Sending BLE State Change: OFF > BLE_TURNING_ON
07-25 21:10:16.446 6251 6267 D BluetoothBondStateMachine: make
07-25 21:10:16.447 6251 6274 I BluetoothBondStateMachine: StableState(): Entering Off State
07-25 21:10:16.448 6251 6267 D BluetoothAdapterService: setProfileServiceState() - Starting service com.android.bluetooth.gatt.GattService
07-25 21:10:16.449 4134 5709 E NearbyDirect: BackgroundBleScanner: Unexpected action=android.bluetooth.adapter.action.BLE_STATE_CHANGED
07-25 21:10:16.454 6251 6267 I BluetoothAdapterState: Entering PendingCommandState
07-25 21:10:16.459 6251 6251 I BtGatt.JNI: classInitNative(L922): classInitNative: Success!
07-25 21:10:16.460 4134 5709 I NearbyDirect: MagicPairScanner: BluetoothLeScanner is null, Bluetooth might be off. Enabled=false
07-25 21:10:16.460 6251 6251 D BtGatt.DebugUtils: handleDebugAction() action=null
07-25 21:10:16.460 6251 6251 D BluetoothAdapterService: getAdapterService() - returning com.android.bluetooth.btservice.AdapterService@f6b587
07-25 21:10:16.463 6251 6251 D BtGatt.GattService: Received start request. Starting profile...
07-25 21:10:16.463 6251 6251 I bt_btif : get_profile_interface gatt
07-25 21:10:16.464 6251 6251 D BluetoothAdapterService: getAdapterService() - returning com.android.bluetooth.btservice.AdapterService@f6b587
07-25 21:10:16.469 6251 6251 D BtGatt.GattService: profile started successfully
07-25 21:10:16.469 6251 6251 D BluetoothAdapterService: getAdapterService() - returning com.android.bluetooth.btservice.AdapterService@f6b587
07-25 21:10:16.469 6251 6251 D BluetoothAdapterService: handleMessage() - Message: 1
07-25 21:10:16.469 6251 6251 D BluetoothAdapterService: handleMessage() - MESSAGE_PROFILE_SERVICE_STATE_CHANGED
07-25 21:10:16.469 6251 6251 W BluetoothAdapterService: onProfileServiceStateChange() serviceName=com.android.bluetooth.gatt.GattService, state=12, doUpdate=true
07-25 21:10:16.469 6251 6251 V BluetoothAdapterState: isTurningOff()=false
07-25 21:10:16.469 6251 6251 V BluetoothAdapterState: isTurningOn()=false
07-25 21:10:16.469 6251 6251 V BluetoothAdapterState: isBleTurningOn()=true
07-25 21:10:16.469 6251 6251 V BluetoothAdapterState: isBleTurningOff()=false
07-25 21:10:16.469 6251 6251 D BluetoothAdapterService: processProfileServiceStateChanged() - serviceName=com.android.bluetooth.gatt.GattService isTurningOn=false isTurningOff=false isBleTurningOn=true isBleTurningOff=false
07-25 21:10:16.469 6251 6251 D BluetoothAdapterService: GattService is started
07-25 21:10:16.469 6251 6267 D BluetoothAdapterState: Current state: PENDING_COMMAND, message: 4
07-25 21:10:16.471 6251 6267 I bt_btif : enable: start restricted = 0
07-25 21:10:16.471 6251 6268 I bt_stack_manager: event_start_up_stack is bringing up the stack
07-25 21:10:16.471 6251 6268 I bt_core_module: module_start_up Starting module "btif_config_module"
07-25 21:10:16.471 6251 6268 I bt_core_module: module_start_up Started module "btif_config_module"
07-25 21:10:16.471 6251 6268 I bt_core_module: module_start_up Starting module "btsnoop_module"
07-25 21:10:16.471 6251 6268 I bt_snoop: start_up Time GMT offset -14400
07-25 21:10:16.471 6251 6268 I bt_core_module: module_start_up Started module "btsnoop_module"
07-25 21:10:16.471 6251 6268 I bt_core_module: module_start_up Starting module "hci_module"
07-25 21:10:16.471 6251 6268 I bt_hci : start_up
07-25 21:10:16.471 6251 6268 I bt_hci : start_up lpm configure value = 0.
07-25 21:10:16.471 6251 6278 W bt_osi_thread: run_thread: thread id 6278, thread name hci_thread started
07-25 21:10:16.460 6268 6268 W stack_manager: type=1400 audit(0.0:19): avc: denied { write } for name="state" dev="sysfs" ino=24019 scontext=u:r:bluetooth:s0 tcontext=u:object_r:sysfs:s0 tclass=file permissive=0
07-25 21:10:16.460 6268 6268 W stack_manager: type=1400 audit(0.0:20): avc: denied { write } for name="state" dev="sysfs" ino=24019 scontext=u:r:bluetooth:s0 tcontext=u:object_r:sysfs:s0 tclass=file permissive=0
07-25 21:10:16.460 6278 6278 W hci_thread: type=1400 audit(0.0:21): avc: denied { read write } for name="ttySAC1" dev="tmpfs" ino=13511 scontext=u:r:bluetooth:s0 tcontext=u:object_r:gps_device:s0 tclass=chr_file permissive=0
07-25 21:10:16.474 6251 6268 I bt_vendor: alloc value 0xd8c0fb99
07-25 21:10:16.474 6251 6268 I bt_vendor: init
07-25 21:10:16.475 6251 6268 I bt_vnd_conf: Attempt to load conf from /etc/bluetooth/bt_vendor.conf
07-25 21:10:16.475 6251 6268 I bt_vnd_conf: vnd_load_conf file >/etc/bluetooth/bt_vendor.conf< not found
07-25 21:10:16.475 6251 6268 E bt_upio : set_bluetooth_power : open(/sys/class/rfkill/rfkill0/state) for write failed: Permission denied (13)
07-25 21:10:16.475 6251 6268 E bt_upio : set_bluetooth_power : open(/sys/class/rfkill/rfkill0/state) for write failed: Permission denied (13)
07-25 21:10:16.475 6251 6268 D bt_hci : start_up starting async portion
07-25 21:10:16.475 6251 6278 I bt_hci : event_finish_startup
07-25 21:10:16.475 6251 6278 I bt_hci_h4: hal_open
07-25 21:10:16.475 6251 6278 I bt_userial_vendor: userial vendor open: opening /dev/ttySAC1
07-25 21:10:16.475 6251 6278 E bt_userial_vendor: userial vendor open: unable to open /dev/ttySAC1
07-25 21:10:16.475 6251 6278 E bt_hci_h4: hal_open opened the wrong number of ports: got 0, expected 1.
07-25 21:10:16.476 6251 6278 I bt_hci_h4: hal_close
07-25 21:10:16.476 6251 6278 E bt_hci_h4: In transmit_data, error writing to the uart serial port: Bad file descriptor

Edit: Just flashed back to the July 18 build (the last one before the 70MB size drop - where I assume unofficial switched device tree) and bt works fine. G935W8.