All this additional complexity, while great for getting an engineer circle jerk going, is mostly irrelevant if you are using the dial for coarse adjustment and

All this additional complexity, while great for getting an engineer circle jerk going, is mostly irrelevant if you are using the dial for coarse adjustment and dialing it in by feel and if your shower is shorter than the time it takes to make your hot water supply change temp a meaningful amount. Shower valves were literally two dumb valves for the first 100yr and they worked fine.