A few more points
If your cold water pressure is fine and your hot water pressure is no good what do you really expect a pressure booster to do?
I would find a LICENSED PLUMBER and have her/him check your hot water supply lines from the heater to see if a valve is partially closed.
Or you may have galvanized piping slightly corroded inside offering some type of restriction
Or make sure your dielectric fittings have been installed properly and in the right locations
Or check the actual faucet to make sure the hot water side is flushed out from possible old washer particles.
If your cold water pressure is adequate then it stands to reason you have some restrictions on the H/W supply
PLEASE feel free to E mail me if you have any more questions.