So, essentially the outlets on the back of the Equitech are wired the same way as old 240V appliances, the kind that had 3-wire cords. Correct?
That seems close, but the house N is not grounded through the Equitech. Or at least should not be. Ye olde (pre 1990s?) dryer DID bond N and ground internally to the dryer. There’s no reason to do that with a balanced conditioner... but I don’t speak for the manufacturers. Who knows what crazy things they do.
The secondary winding on these isolated devices is split. The center of the two coils is bonded to ground, so the outside ends of the 2 coils are each equal and opposite 60VAC.
And herein is a problem which the founder of Jensen transformers wrote about ages ago, that there’s still the possibility for a ground loop. Ooops.
Anyway, what floating ground load?