Side stand
What? Are you talking about rear stand or side stand?
I mean, if you're looking at the sight glass while on the side stand, you're gonna overfill.
If you're looking at the sight glass while on the center stand, or on flat ground; the difference is negligible.. This is per my experience of about 12 oil changes, in which I've filled the bike on center stand, started it, checked it, then lowered to both wheels and checked again. It's always the same.