Maybe I'm missing something, but there's no DC wiring in the walls in our bedroom. The default install is a single AC hot, neutral, and ground running to the fixture. We have an extra (unused) hot because the old AC fan had separate switches for the fan and light.

What I'm proposing is taking that unused extra wire, wiring in either a separate AC fan controller, and letting the fan controller in the fan take that as an input (drawing essentially zero current), and adjust the DC output based on it. No DC outside the fan itself (as it is presently), no need to pull another wire. On the downside, now your soft remote and hard AC fan controller can be in disagreement.

We have no Z-wave in the house, but I appreciate the tip.