Duane Bozarth wrote:
....
I went to dozens of home with finished basment stairs. Nobody did
anything special. They just add carpets or laminates. A few did replace
the raw treads with finished hardwood treads. But those raw treads are
easily replacable.

That doesn't mean they met code (obviously)...
....

I meant to add that unless the mismatch is really noticeable enough that
you see people actually mis-stepping, the exact compliance to code is
pretty much a non-issue until/unless one of two events (both fairly
remote, but possible)--

1. You get ready to sell and the buyer has a lender w/ a persnickety
inspector who notes the discrepancy. You would normally end up taking
some financial hit to compensate for the fix or choose to repair it at
the time on your own, or

2. Somebody actually does trip/fall, gets injured and sues...might
become a liability issue w/ an insurance company if did work and didn't
comply.

The likelihood of either is, as noted, relatively remote in a borderline
case--if it ends up being quite a bit out, it will probably be obvious
there's a problem that should be addressed...otherwise, your call.