[Moto G 2015 Android Development] MSe1969:
If you would like to migrate (aka "dirty-flash", i.e. no factory reset) from one of the build variants of this thread to the new LineageOS 16.0 builds, please follow the instructions below, depending on your currently used build flavor. Testing looked good, but

I won't give you any guaranty that everything works out 100% as desired

(e.g., you will have to re-enter your WiFi passwords). So make a nandroid backup before and have a "Plan B" handy (in the worst case, be prepared to make a clean install). You may have to re-configure Bluetooth or WiFi in some cases, but your main stuff should be there.

Note:

It may happen, that your lock screen PIN or pattern is not recognized any more! In that case, you don't need to wipe/clean install - just boot into TWRP and delete the file /data/system/locksettings.db and reboot. You will then have to set a new lock screen protection.

A. Default LineageOS 14.1 with substratum and microG patch

Download Migration Build A and copy the ZIP to your Internal memory or SD-card.

Only if applicable:

Download any additional flashable ZIPs, which usually have installed a "survival script" and would usually re-flash themselves after each update, like e.g. Magisk or Gapps and copy the ZIP to your internal Memory or SD-card. Make sure to download the Android 9.0 (Pie) version (e.g. for Gapps) . . .

Switch off any automatic updates

in Play Store, Magisk or whatever app offering that feature!

Boot into TWRP and wipe the /system partition

Flash the Migration Build A and confirm afterwards to wipe cache&dalvik

Only if applicable:

Without rebooting, flash the stuff you've downloaded before (like e.g. Magisk, Gapps, . . .)

Reboot into your system and continue with the last section below D. Final steps

B. Hardened build with pre-installed microG and F-Droid

Download Migration Build B and copy the ZIP to your Internal memory or SD-card.

Only if applicable:

Download any additional flashable ZIPs, which usually have installed a "survival script" and would usually re-flash themselves after each update, like e.g. Magisk and copy the ZIP to your internal Memory or SD-card.

Switch off any automatic updates

in Aurora Store, Magisk or whatever app offering that feature!

Boot into TWRP and wipe the /system partition

Flash the Migration Build B and confirm afterwards to wipe cache&dalvik

Only if applicable:

Without rebooting, flash the stuff you've downloaded before (like e.g. Magisk, . . .)

Reboot into your system and continue with the last section below D. Final steps

C. Above hardened microG build with substratum patch

If you have active substratum theme(s), completely deactivate and remove them - all needs to be cleaned out! If unsure, visit the respective support thread.

Afterwards, uninstall all theme apps, and uninstall the substratum app itself.

Reboot your system and continue with the steps outlined for build variant B above.

D. Final steps

Check the result, once your system is up & running. The main stuff should be there - whatever you do, keep in mind that the migration build is not intended to be really used, it is not safe!

Whatever you do, DO NOT update any app!

The Updater app should offer you a ROM update. If the result looks acceptable to you, simply choose the OTA update and let the updater do its job = done :good:

If the result is a mess for you, either restore the nandroid backup to get back to Nougat or make a factory reset and directly flash the LineageOS 16.0 build from the linked thread.

Once again, don't mess around with the migration build too long, it only serves the purpose to take over your data.

Good luck ! :)