I did some digging and 20 inches is the max.
Maybe 22 is possible, not sure.

I decided to go with 18 inches.
It's the second picture from the top.

Apparently these wheels came off E90, and then were on 2008 E70.
I don’t understand how, given the hub is bigger on E70

But if they're in face from E90 with 72.56 diameter, would they work on E53? At this point I think it's only the offset I'd have to worry about. If they fit when I try them on is that fine, or do I have to worry about anything else.