Either the wax or the waxless should work.
It needs to be sealed, top to bottom, so if the wax is squishing, you should be okay.
I've got a Toto Aquia that's about to be reinstalled after a bathroom remodel. It looks to be a flush to the floor flange situation that I'm installing it on. More or less anyway. It's not PERFECTLY level either, a little bit higher in front than the back. It used to sit up off the floor a bit more, but the remodel raised the floor slightly, so now it's more flush.
So two question. First, the flange and piping I have is all copper stuff. How much can I hammer on that to get the flange level without breaking any seals? Or is that necessary?
Second, am I going to need a flange spacer to get a good seal or will the wax ring still work ok? I also contemplated getting one of those waxless rings with the gasket instead, since it seemed like the flush flange with wax ring sealing issue wouldn't even be an issue. Would that work better or do those have issues with going bad over time? I know the wax ring is tried and true, and I don't want to have to be replacing that other gasket every few years or something, if it's not necessary.
Yeah, I installed it myself before the remodel on the old floor. I think the flange was about 1/2", maybe 5/8" (a little high) off the ground before, so the lip on the plastic piece went down over the flange and created a good seal. I think it'll be fine, just wanted to see if there was any info out there before I reinstalled it.
I thought about trying the waxless gasket because I didn't want to get that nasty wax all over my new tile. It's underneath the toilet, I know, but I'm picky.
BTW, love the Aquia (you sold it to me, Terry) and haven't had any problems. I'd say about 95% of small flushes work for #2 as well (at least ours). I did, however have some leaking on my first install try. I emptied it all out and took the tank off and sanded the bottom by the holes like you recommended. After that, it worked like a champ. Just in case anyone is installing one by themselves. Do that step as a precaution.