Except you think the HHKB has a plate....
Is that relevant at all? I've owned one and like every other one, it has a plastic backing behind the keyboard. Not sure if that's technically 'not a plate', but that doesn't change my experience with it in the slightest.
It can have both a plastic backing behind the keyboard and a plate..so not sure what either of those two have to do with.
It doesn't change your experience..but given you've been wrong (factually) about the rubber domes in Topre and the plate that the HHKB apparently has according to you..and then describing what a plate would actually be...
But let's talk facts
Topre Rubber domes DO have variability..they're not all the same. (You said this statement was wrong, it is true).
HHKBs do NOT have a plate.
Plastic backing behind a keyboard - based on that description, it is not a plate at all...or maybe your description is just poor.
I mean, anyone that's owned a HHKB can see it doesn't have a plate..heck, anyone that's seen one with the keycaps off knows it doesn't have a plate even in pictures....How do you NOT know it doesn't have a plate if you own one? No idea...