Just as an aside...

The times I've gotten almost-burned taking a shower, were
always with a one-handle control.

Seems if you move it towards "hot", it gets _very_ hot
unpredictably.
If you move it towards "cold", it gets _very_ cold,
unpredictably.
Almost impossible to control it in small increments of
temperature.

With a two-handle (hot/cold) control setup, you can set "one
side" (say, the hot side), and then gradually add cool water
to balance things out.

I would never want a single-knob control.