Regarding the argument on "Flow restrictors" or regulators.
I do not listen to gossip or rumor or lies. but put a GAUGE on the thing
Hydrant/Faucet--Regulator--Y--RV and Gauge.. A genuine WATTS pressure gauge (usually I've used other brands)
The 3/4" cylinders are REGULATORS. oh they restrict flow too but from static to about 1/2 to 1 Gallon per minute they hold the pressure at the pre set Usually about 45PSI. no sign that they let it increase less they are old and wore out.
Problem is shower takes TWO Gallons per minute.
You want a "Flow Restrictor" A washer. that's all it is, a washer.