I don't know which is more annoying, the fact that the nanny state or the lawyers got to the faucet manufacturers and encouraged them to provide mixing valves in the faucet or the fact that society is so litigious that there was no other choice.
Gone are the days of selecting the temperature of our own hot water. That is progress?
Even if your new faucet has a built in mixing valve, I doubt that running the system pressure at 35 psi versus 60 psi would have any affect on the valves performance as mixing valves work by you varying the port size (by turning the handle) of the hot and cold water to arrive at the desired temperature.
Once this temperature is set, if your faucet has one, a paraffin filled tube automatically adjusts the flow of hot and cold water to keep the desired temperature.
Even pressure balancing valve reacts to the difference in pressure between hot and cold, not the total pressure.
Here is a better explanation.
The OP noted that there is plenty of water pressure everywhere else and that all other sinks have ample hot water flow, while the new faucet is lacking hot water pressure.
I doubt it but does the new faucet information say that there is a pressure reducing valve built in?
Or could the explanation be this:
When your boat was built the taps were designed to pass through almost the full flow of water supplied by a single1/2" pipe. Those were the good old days.
Today the supply connection tubes provided by the faucet manufacturer and the port sizes within the faucet itself are much smaller and as a result flow is much less. Thanks nanny state.
The pressure will drop a little through any faucet due to the restriction and the aerator.
Although both are important and have an impact, just don't confuse pressure with flow.
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