Comment by jerkstate

Thermal regulating shower/bath faucets are relatively common: https://www.deltafaucet.com/design-innovation/innovations/sh...

I have one in my master shower and it's fantastic. Of course, the water starts out cold (because the water in the hot water pipes are cold) but once it's up to temperature, it's very consistent, even if you have a toilet flush in your house which would reduce the pressure of cold.