2.88MB was supported by most drives and was usable under Linux. You were supposed to use proper 2.88MB floppy, but you could usually get away with using a 1.44MB floppy and reformatting.
I'm not entirely sure how well they were supported under Windows though.
IIRC the Windows 95 install floppies were 2.88MB. With that in mind it's probably safe to assume that they were at least readable even in DOS, although I don't recall being able to format or write to a floppy at that capacity in any version of DOS/Windows.
I'm not entirely sure how well they were supported under Windows though.