Completely impossible.We can't really know this unless we play on both android and ios devices, but it seems as if each "improvement" for ios problems screws up the android servers even more. Any chance you could just give android the old game back since it was Apple that required the Unity update in the first place?
That would be nice, but because of the whole cross server implementation, any changes made to the game have to be done for both platforms.
Theoretically, if cross server play was not a thing, I suppose it would be possible to run an old version of the game on Android servers...but that's a stupid idea, because from that point on, Android would not receive any more updates (or likely any Support attention). VR is way too small to run what would essentially be 2 different games at that point.
