Just turn on the hot water first to desired pressure, then turn on the cold water to get temperature

Edit: because you really don’t need much cold water to cool it down.

Edit 2: then as the shower cools down over time, just turn down the cold water a little bit as needed

Edit 3: and because you’re able to control overall pressure, you can have exact temperature to a trickle or full power, allowing you to have as long or powerful of a shower as you want