Terrain following added to APM:Plane --> To Multicopters?

Saw Andrew Tridgell’s Blog on “Terrain following added to APM:Plane”. I can see a need for this feature when flying way points or in terrain that is not flat.

Great idea for the Planes, but also wondered if this is being discussed for Multicopters?

My hex application requires sonar, which worked very well on 2.9.x with APM 2.5. I upgraded to Pixhawk this spring, so I’ve been anxiously waiting for 3.2-rc3 and/or -rc4. Problem is I cannot get anything past -rc2 to fly on my 3DR hex. Seems to me that some kind of motor/ESC issue was introduced in -rc3 that persists in -rc4. If I load -rc2 or previous, it flies perfectly, but alas, no sonar. If I load -rc3 or -rc4 it simply will not fly - strange motor/ESC behavior. At my wits end, tried everything I can think of, still no-go… Sent in logs, etc., on the beta site, and I know the Dev’s are super busy - for which I thank them - but I simply cannot find/resolve the issue. Maybe -rc5?

I would really love this function for multicopters, especially if it were to include multi sonar support.