[Sprint Samsung Galaxy S6] tdhite:
[KERNEL] [ROOT][MM | N] [SM-G920P] [29-May-2017] SkyHigh Kernel (Port) [v4.99]

Magisk has been perfect for me, so I would surmise it will be so for you. The root hide feature is flawless as well with the kernel, so all things are a go for Magisk imho.

As for Secure Storage -- I am genuinely mystified, but getting there I think. There appears to be a JNI change between Nougat securestorage code and (marshmallow). See these logs (nougat first, marshmallow second -- note the JNI 'skip' call that is not in nougat). I have to dig in to the system libraries further to see WTH is going on in there, but the kernel is working fine -- not stopping anything in the process of bluetooth starting, it's system libs somehow.

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Client SS library: connect: No such file or directory

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to SSD socket

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to Secure Storage Daemon

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Connection was not prepared

06-01 19:04:08.405 30349 30374 E SecureStorage: [ERROR]:SPID(0x00000000)Error processing data

06-01 19:04:08.405 30349 30374 I SecureStorage: [INFO]: SPID(0x00000000)Processing data

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Client SS library: connect: No such file or directory

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to SSD socket

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to Secure Storage Daemon

06-01 19:04:08.405 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Connection was not prepared

06-01 19:04:08.656 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Client SS library: connect: No such file or directory

06-01 19:04:08.656 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to SSD socket

06-01 19:04:08.656 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to Secure Storage Daemon

06-01 19:04:08.656 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Connection was not prepared

06-01 19:04:08.906 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Client SS library: connect: No such file or directory

06-01 19:04:08.907 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to SSD socket

06-01 19:04:08.907 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to Secure Storage Daemon

06-01 19:04:08.907 30349 30374 W SecureStorage: [WARN]: SPID(0x00000000)Connection was not prepared

06-01 19:04:08.955 30349 30367 I Process : Sending signal. PID: 30349 SIG: 9

06-01 19:04:08.979 5949 8347 I ActivityManager: Process com.android.bluetooth (pid 30349) has died(83,975)

06-01 19:04:08.980 5949 8347 D ActivityManager: cleanUpApplicationRecord -- 30349

06-01 19:04:08.981 5949 8347 W ActivityManager: Scheduling restart of crashed service com.android.bluetooth/.gatt.GattServi

ce in 1000ms

10-19 13:08:46.908 24883 25180 W SecureStorage: [WARN]: SPID(0x00000000)Client SS library: connect: No such file or directory

10-19 13:08:46.908 24883 25180 W SecureStorage: [WARN]: SPID(0x00000000)Could not connect to Secure Storage Daemon

10-19 13:08:46.908 24883 25180 E SecureStorage: [ERROR]:SPID(0x00000000)Error processing data

10-19 13:08:46.908 24883 25180 E SecureStorage: [ERROR]:SPID(0x00000000)Android: read data error: -3

10-19 13:08:46.908 24883 25180 I SecureStorage: [INFO]: SPID(0x00000000)Skip using SecureStorageExceptionJNI

10-19 13:08:47.108 24883 25180 I SecureStorage: [INFO]: SPID(0x00000000)Processing data

More debugging this weekend, but securestorage is not honoring the ro.securestorage.support property, rather seems to be forcing its will on things.