Ohhhhhh! Prebate is just another word for subsidie, welfare check! I think people forget that when you get money from the government along come all the strings that bind you into slavery.
It’s like in the movie “Blade Runner” where in that universe the word for executing a Replicant was called “retirement.”
Yes, it's clearly a subsidy. It subsidizes the putative amount of Fair Tax that one would have to pay to maintain one's self at the poverty level.
I believe that you would inevitably start hearing calls to "means test" this subsidy, just as you now hear about Socialist Security.