Comment by mauvehaus

> There's no clean mechanism to control a fan's speed in-band on a normal AC wall switch.

There absolutely is. If you have a fan with a light controlled by separate wall switches, you have two hots running to the fixture. Take one, and leave it unswitched always on to the fixture, and use the second switch (or fan controller) and use it as an input to the controller on the fan. Done.

Unfortunately, I haven't seen this implemented anywhere.

This message brought to you by the hours I've spent annoyed by exactly this misfeature in our new bedroom fan. Fanimation does sell a wall mounted remote that can be wired inline with a switch, so at least there's a single point for master power and a remote you can't lose. Unfortunately, there's a noticeable delay between flipping the switch and the light turning on.