We have one that has a rather long pipe run with just enough drop to pass code.. in 1958...
The 1.6 GPF plugged all the time. If not the toilet it’s self it would clog in the pipe.
I acquired a new 5 gpf toilet (it pays to know people in the business. it was collecting dust in the back of the shop)
But now when you flush that thing, water pressure in the house (I have a private well) drops, lights dim as the pump tries to keep up and doors to the bathroom rattle. It’s been there a little over a month. Haven’t needed the plunger or the snake since.
The Romans had the clean water and sanitation thing right. Europe has played with the idea but... I'm not sure they really understand it.
/johnny