Sorry should have used 3 gpm, for a shower, not 10 gpm.
At 3 gpm the loss in the 3/4" pipe is only 2.47 ft/hundred feet, so 2.1 PSI. Which doesn't seem like as big of a deal, and maybe youd be fine doing nothing. Maybe plumb in a tee with a pressure gauge on one end and a shower head on the...