FP Open - most elegant way to install microG (w/ sig spoof)?

Before I start: yes, I have seen the other topic on this issue. Thanks to the bot automatically closing “old” topics (why?! I never understood why some forums and bug trackers insist on doing that), I have to make a new topic.

I'm currently using the microG fork of LineageOS on my FP2 since that seemed to be the easiest and pain-free way of running microG. I do prefer FP Open over LineageOS for a few reasons, mostly unrelated to my question.

Before I moved over to LOS+uG, I did manage to painstakingly get signature spoofing working on FP Open using Magisk; it was clunky, required patching one of the RO system images (boot.img?), replaced the system-provided su with its own and required the installing 2 or 3 Magisk modules to actually work. A house of cards that I’m fairly sure would collapse with the next update, if updating in this state was even possible.

The question is not “how do I install microG on FP Open”, but rather “is there a better way to do so than what I’ve done”? I’ve seen that people used to patch their ROMs before they were “odexed” (whatever that means). Now that’s no longer an option, is Magisk/Xposed really the only way? Is there a way to update my system with them installed and/or have them not install their own su implementation?

A post was merged into an existing topic: What is 2021 with OS OPEN Android 9 the way for signature spoofing