No. At least not according to the purveyors of such systems. The inlet pressure is much less than the booster output. But the booster can adjust to the inlet pressure. The extra water will defuse through your pipes ending back in the membrane for multiple passes. It is easier on th membrane than the original plan, as it dilutes the waste into the incoming feed wate, and is not concentrating much. A shower can be taken at the same time and neither the membrane or the showeree would suffer. Keep in mind the waste is still passing a flow restrictor, and stepping sown it's pressure a little. Water can not compress much at all, anfd a properly made/maintained waterheater will handle any increase. Plumbing after the heater will result in water backfeeding from the hot into the cold, and may excessivley warm the r/o systems water depending on orientation.