I just visited some web galleries of bathroom remodelers in the US, and it looks uncommon to have external shower fixtures. They tend to bury as much of the fixture as possible in the wall. From the photos, I don’t get the impression they are using thermostatic mixing valves. But it’s hard to tell. Can anyone confirm or deny?
I think I might favor external fixtures because they tend to be much cheaper and also more easily servicable.
I have not seen that in the US and didn’t know it existed, but I have not really looked anywhere other than the usual home Depot or Lowe’s, so I don’t know what new home designers are doing. We just installed an electronic version that has temp, volume, and wand vs overhead switch controls and presets on a wall mount thing. Of course it comes with an app, but we just use the controller on the wall. Maybe not as dependable as a mechanical control, but works fine so far.
Most controls I see in the US, like in houses and hotels, are all-in-one type things where you basically have to have max volume to get hot water. Usually inside the control you can set a max temp that limits the percent hot water in the mix. Some have separate volume and temp controls, but I don’t know if they’re doing anything fancy like you describe; and a few old homes have separate hot and cold knobs, but that’s rare.