Were good on opening/swinging stuff. Were both fairly long legged so our feets wont be hanging out.
As too rocking on the Thetford clearance between the bolt hole bosses underneath and surface of flange is zero or exactly enough for thickness of flange. So if flange warped or floor drops away, perimeter edge of toilet wont reach =rockage. I can only guess because its plastic, once it contacts flange cant pull toilet any tighter by the bolts.
Shimming I had thought about though I needed to remove to make sure stuff ok but after seeing toilet wedges might break the rather thin shell. Full spacer, say thin disposable cutting board sheet might work.
Only saving grace is the gasket is foam, otherwise like toilet in our home, I have to replace wax ring at least once a year.
Next time Im using one of these, then toilet and flange should stay sealed, move independently of plumbing underneath which cant move. Also let me cut pipe shorter, had to make a spacer under toilet as flange is now 3/4" above floor.
Ya joy of plumbing...I actually enjoy, water lines, gas lines, air lines- anything but toilets :)