I don't know about TP sheet count, but you are limited by law on how much water you can use to flush, and that's federal .
Aren't you glad you live in a "free country" ?
+1
Which is an excellent example of the folly of gubmint sanctioned regulations. They set a limit on water flow for toilets per flush, not realizing that because there is less water flowing, it takes more flushes at times to get the job done, thus negating the savings.
I had to replace the ball flapper for the flush valve in one of our toilets the other day and all the store had in stock were "flow saving" models (adjustable to regulate the close rate of the flap to limit water consumption).... it makes it difficult (even on maximum flow, to flush a couple of kleenex tissues. We use three times the water as we used to, which isn't a large issue since we are on a private well, but it makes it aggravating to have to wait for the tank to refill to re-flush.
My next mission is to visit a couple of "old timey" local hardware stores to see if they have some older stocks of flappers.