Well i tried Tingle, that seems to fail with because the file mount of /system does not work, it seems that maybe /system here is mounted as /system_root (sorry i often get a bit lost in Android mounts)!
I tried Nanodroid, as an installation under Magisk it gave me the boot loop (the lineage boot line ran for a long time and eventually drops into TWRP)
I tried NanoDroid from TWRP that again fails because it can't find the files to patch.
Sorry not to include lots of logs and messages here I thought I would start with a quick question to see if it had been done. There is an entry in the microg wiki saying it can't be done above android 10 , yet the patching systems above imply they will work.
I could of course take the device tree and TRY (i've never done it before) to build my own patched rom based on your work, however early days so maybe there are working options out there that I just haven't found yet!