Wow one of my favorite FLOSS developers replied to me! Hopefully they (lineageos) adopt it, it would be a HUGE improvement over the native android VPN options and openvpn.
Would adding such a module break SafetyNet? Can you even add modules to the Android ROM / Kernel and then relocking bootloader and disabling root access?
Not everyone cares about 'safetynet', and LineageOS does not support secureboot-style locked bootloader booting.
You can literally build the ROM with any kernel modules you want, provided the module has been backported to the almost-guaranteed ancient kernel your device needs for initializing/using its hardware.
I wonder if LineageOS plans to include this module..