What is the correct height of a toilet flange relative to the finished floor?
The original intent of the toilet flange is to screw down to the finished flooring, not below it, definitely not shimmed up above the finish floor, although there is a small bit of room if there is a small error in the install, say no more than 1/8"-1/4" Remodeling has made it a regular practice of setting the flange below a newly installed finish floor where the toilet was already in place. Larger (taller) wax rings or doubling get past that issue. And with that in new construction, setting the flange on the subfloor has become acceptable, also setting it below the finished floor.