If you still don't see any of the above evidence, yet you're still concerned...put a drop of stripper on the tile behind the door for 5min. If the clear liquid clouds up, you have wax on the floor
I found an article regarding testing for wood floors.
it said place several drops of mineral spirits (paint thinner) on floor for several minutes, wipe up with a white towel if there is brown or yellow residue or it feels waxy.
Second test was drop a large drop of 1/1 water/ammonia on floor, allow to sit 5 minutes. if area turns white, a floor polish or wax is likely present.
I know wood and ceramic are different, but are there multiple types of waxes that people have put on floor tile?
I haven't found anything about testing for waxes on ceramic floors. With all the collective wisdom here, I figure there are things learned I can't find any internet search.
Is visual and stripper testing the only methods I need to do as part of pre-inspection?