Follow up of my post from earlier this month in case someone needs in the future:
Got myself a Pi5, flashed KonstaKANG’s AOSP 16 fork, and installed the “universal” APK of Grayjay.
Tested some 10 or so videos, and so far, been working pretty much the same as on phone, including third party plugins.
Only exception I observed is that it’s stuck in landscape mode, and I expect (yet to test) that it stays like that until I use some program to force the screen to rotate.
I use Grayjay on my MNT Laptop (arm64) in Linux through Waydroid. A native client would be better but the solution with Android emulation works a treat. No issues.