At both taps full open you have full flow/pressure from both the hot water and cold water supply only restricted by the valve full open orifice.
Now add an additional valve to the mixed outlet of the faucet with both hot and cold feeding into the line that runs into it. If the valve is sized to accommodate the full flow from both valves feeding into it, the full combined pressure/flow from both cold mains and hot supply is available.
Also, once you set the temperature you like by turning the temp taps, that temp will be available to you at any flow rate on demand. Nothing you do to the mixed valve will change the temperature of the flow. This is especially useful if your hot temperature is very hot, you can have nice warm water to wash your hands every time without worrying you might scald yourself.
zheres your standard two tap mixer faucet:
At both taps full open you have full flow/pressure from both the hot water and cold water supply only restricted by the valve full open orifice.
Now add an additional valve to the mixed outlet of the faucet with both hot and cold feeding into the line that runs into it. If the valve is sized to accommodate the full flow from both valves feeding into it, the full combined pressure/flow from both cold mains and hot supply is available.
Also, once you set the temperature you like by turning the temp taps, that temp will be available to you at any flow rate on demand. Nothing you do to the mixed valve will change the temperature of the flow. This is especially useful if your hot temperature is very hot, you can have nice warm water to wash your hands every time without worrying you might scald yourself.