[Razer Phone ROMs, Kernels, Recoveries, & Other Dev] -SKYLINE-:
TLDR version: Unlocked bootloader, used Lineage Recovery to flash Lineage OS 16, MindTheGapps and Magisk. So far so good. I listed some quirks below to help save others time.

Finally got around to unlocking the bootloader and flashing with official lineage 16.

The last time I flashed a phone was my Oneplus One and before that my Galaxy S2. I decided to go with the official Lineage Recovery (mainly because no idea if official Lineage 16 has OTA and whether any such OTA is compatible with TWRP. Any one know if this is actually the case?). I used MindTheGapps simply because OP said so.

For those sort of new to recent ways of flashing like me, I followed the OP and official lineage installation instructions using Windows 7 (I started with Windows 10, but my old computer was taking too long) which had the following minor quirks (took me like a day to search online and find out what to do):

When following the ADB and fastboot guide to install adb and fastboot, step 5 of the universal adb driver may require you to go into your Windows device manager to manually select the adb driver (forgot the exact name) from the list and device drivers under Google after connecting the usb cable when attempting adb (and similarly to manaualy select the fastboot driver (forgot the exact name) after connecting the usb cable when attempting fastboot/download mode.

When unlocking the bootloader using the ADB and fastboot guide,

fastboot oem unlock

did not work for me. I had to use

fastboot flashing unlock

. Source from TWRP for Razer Phone (cheryl) guide, but did not end up using TWRP.

Following the Temporarily booting a custom recovery using fastboot guide, in Step 5, rather than

fastboot flash boot <recovery_filename>.img

, I followed the note for Windows

Following the Installing LineageOS from recovery guide , Step 3 after hitting

Wipe System

, the screen just quickly seemed to finish wiping the system, but when I started Step 6

adb sideload filename.zip

it showed

-- Wiping system...
Formatting /system...
E:can't give path "/system" to format_volume
System wipe failed.
Stopping adbd...

Not sure if that is normal, but so far Lineage seems to be running fine.

Following the Installing LineageOS from recovery guide , apparently there is a bug in the Lineage Recover on the progress %. Mine only goes up to 47% and then says

Total xfer: 1.00x

. That apparently is normal (source). I just continued onwards.

Following the Installing LineageOS from recovery guide , for Step 7, I had to repeat

before using MindTheGapps (I suspect this applies to any Gapps). Seems to be working fine.

Following the Installing LineageOS from recovery guide , Step 8, I had to repeat

before flashing Magisk.zip. This is my first time using Magisk and this process appears to give root and installs Magisk Manager as an app before your first boot.

Because the phone is on LineageOS, Magisk will show that SafetyNet fails with CTS profile failing and basic integrity passing. I installed via Magisk Manager the MagiskHide Props Config module (and the stated prerequisite module, i think it was just the terminal emulator) and used the terminal following the instructions to change the device fingerprint to the one for Razer Phone.

Some of my apps needed the Magisk Manager to be hidden (i.e. repackage the app to a different name). However, when opening the repackaged Magisk Manager, it would repeatedly say

but after clicking "OK" that popup just repeats and I couldn't get into Magisk Manager. I simply uninstalled the repackaged Magisk Manager and installed it again and my settings and modules remain. It seems to be working but not sure why this happens. Anyone know if there is another way that doesn't involve uninstalling and installing Magisk Manager?

Double tap to wake doesn't seem to be working for some reason.

Some users (1 and 2) previously responded to my earlier question on whether exFAT (i.e. sdcards above 64GB) work. FYI, there is a module on Magisk for Oreo 8.1 but not for Pie 9.0 which is Lineage 16... so I couldn't get exFAT working. Anyone know if there is a way to make exFAT work on Lineage 16? I know Microsoft has / will be open sourcing their exFAT driver this year, but I don't want to keep my fingers crossed for it to be implemented in android or Lineage generally.

PS - before unlocking bootloader, I tried using Helium to backup my app data. Don't rely on it. Just go in expecting app data will be lost. Google's backup.... well it seems to do a better job than Helium for the apps it does backup.

Going to explore the following things next unless someone already has a solution and can share with me:

Getting Apt-X for bluetooth headset via Magisk (EDIT: the Magisk module Bluetooth_stack_audio_bitrate_changer_for_SBC_+_aptX_&_aptX-HD_enabler-v5.5(10).zip seems to do the trick)

Finding a good GCam / google camera app compatible with Lineage 16 (EDIT: see post #190 below on BSG v2.0.0 (2019-09-30), but my preference is the older BSG v1.3.2 (2019-04-11))

Good luck everyone! Lets keep development and knowledge sharing for our Razer Phone (Cheryl) going!