toilet). Ideally, you'd want to reset the flange to tile height, but I've seen
a lot of folks just double up on the wax rings (asking for a blowout, if you ask
me, but amazingly it seems to usually work).

There's no particular reason why a doubled ring should be a problem,
if the rest of the system is working properly. Waste dumps out of
the toilet and down the drain pipe under gravity, and THAT part
out to work fine with no seal at all. The wax is just to keep
sewer gasses from coming up the pipe, and oout from under the toilet.