... a Bud asked me this .. just curious what some have done.

Yes 10 over is the max (& will work fine) otherwise they'll be slightly oval even w the gap filed down (which you do also w the 10 overs) if you use more than 10 over. Do check the oil ring tension & crimp the expander "links" in a bit if needed. the oil ring top/bottom rails always have adequate clearance

Going "oval" ? ... so that extra 005 would make a diff? .. (many builds have a 005 over ring available).

And as far as ring-drag ? ... that is not that bad of a thing. It is better than "weak" rings. I have fond-memories of my dykes-ring motor from way back when .... almost 120 mph (1/4 mile) through the muffs ...on a drive-out car.

It can be done but I know that I would want to be careful on having adequate ring gap. Squeezing that ring down may close the gap a little tight. Too little ring gap can get nasty.

How about 24 rings unless you have a 4 ring piston. The oil control ring is considered a single ring. Piston has 3 ring grooves.

... maybe it is considered "ONE RING" but there are TWO oil-rings in that one groove in each piston.

I believe after a few run cycles they will have conformed to the new bore. I'd do it if I couldn't find a low priced set on the 'bay. But I'm on a very limited budget.
I once rebuilt a toyota FE landcruiser engine and bought the rings first oversize which is about 10 over so I could file fit them on a used bore/used piston combo. It never gave any problems.
If he's worrying about a few hundredths in the quarter, don't do it.
R.
PS: The oil ring is considered to be one ring, that's true. But if you're file fitting them you have to do each ring individually so you will end up working on 32 separate items plus the expanders.