[HTC 10 ROMs, Kernels, Recoveries, & Other Developm] lalu:
EDIT: After a long night of downgrading / restoring to stock and getting back, I can obviously say that the issue I had was all my fault and it probably has nothing to do with the ROM, but most likely with the firmware.

I'm on 3.16.401.2 (which is O firmware, right?) and with dmesg|grep fingerprint I get

[ 120.733792] init: Received control message 'interface_start' for 'android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint/default' from pid: 787 (/system/bin/hwservicemanager)

[ 120.733851] init: Could not find service hosting interface android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint/default

[ 120.737709] init: Received control message 'interface_start' for 'android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint/default' from pid: 787 (/system/bin/hwservicemanager)

[ 120.737750] init: Could not find service hosting interface android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint/default

[ 122.204062] init: Received control message 'interface_start' for 'android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint/default' from pid: 787 (/system/bin/hwservicemanager)

[ 122.204121] init: Could not find service hosting interface android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint/default

[ 133.327471] type=1400 audit(1560284468.152:412): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0 duplicate messages suppressed

[ 133.419693] type=1400 audit(1560284469.152:414): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 135.324951] type=1400 audit(1560284470.152:415): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 135.418329] type=1400 audit(1560284471.155:417): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 136.184053] type=1400 audit(1560284471.155:417): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 136.425585] type=1400 audit(1560284472.162:420): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 136.580538] type=1400 audit(1560284472.162:420): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 137.427505] type=1400 audit(1560284473.165:422): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 142.519148] type=1400 audit(1560284478.172:427): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0 duplicate messages suppressed

[ 143.435405] type=1400 audit(1560284479.172:429): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

[ 147.421349] type=1400 audit(1560284479.172:429): avc: denied { read } for pid=1087 comm="android.hardwar" name="soc:fp_fpc1155" dev="sysfs" ino=24263 scontext=u:r:hal_fingerprint_default:s0 tcontext=u:object_r:sysfs_fpc_irq:s0 tclass=dir permissive=0

no matter if I set SELinux to enforcing or permissive (I made the init.d script with 3 seconds delay).

So... basically what happened is I dirty flashed the first OTA update, without reinstalling GApps and I couldn't boot anymore. I also didn't have access to MTP in TWRP, no GApps zip in Downloads (stupid me) and my SD card is probably really bad and every time I was trying to flash stock firmwares, I got Error 22 or something related to the target system not being able to downgrade (I'm S-ON)(sorry, can't remember exactly, it was a month ago or so). So I formatted the /persist partition and was able to boot again (again... can't remember what with).

Thank you!