Ok, cool. I’ll pull that in, build it for heli and give it a try.
As @Rob_Lefebvre pointed out, frame lean angles do apply to heli too in acceleration. But the math is different than multirotors. The Loiter (and most other flight modes) will limit what a helicopter can do. But under normal conditions (rate mode) if you build speed with a heli, for instance, pull back gently on the elevator, it will do a nice big 100 foot diameter loop just like an airplane. It’s just simple collective management - do a dive to build speed, lead with a little collective pull back on the elevator and hold it. As the heli goes vertical ease off on the collective to zero pitch, as it goes thru the top of the loop ease into the negative pitch a bit (only takes about -3 degrees). Let it come around, ease off the collective back to zero. All the while holding the same amount of nose-up elevator. As it comes around the bottom go back into positive collective, let off the elevator and it comes out right where it went into the loop (if you did it right). And it doesn’t lose much speed in the loop. Even a heavily loaded UAV will do a pretty nice loop if you build enough speed in the dive.
Now, what makes it interesting with heli’s is that a flybar will corkscrew off the top of the loop so you have compensate with a little roll with a flybar to keep it wings level in the top of the loop. FBL doesn’t do that. A flybar reacts to torque and collective/cyclic pitch changes differently from a FBL head - especially when you invert the rotating plane of the flybar, which is what is steering the head. Or make a sudden pullup on the elevator with a flybar, will react differently from a FBL.
The point is, the flight dynamics of helicopters are more like airplanes, and then we have more than one type of helicopter. Changing the AoA of their wing has a different effect than it has on a multi in what it will make the aircraft do. That’s what will make translating lean angles to acceleration very difficult to apply to both multirotor and helicopters in the same package. If you carefully study a helicopter in 3D flight it becomes apparent how hard it is to apply lean angles into the calculations. Matt is easily pulling 9-10G’s with rapid changes in cyclic and collective here flying just an old flybar with only a tail lock gyro on it. Part of learning how to fly a helicopter is learning how to be really, really smooth. Because if you’re just a little bit aggressive with it, this is what they do. Like in your vid of of your multi - making rapid full stick input and then letting the stick self-center and bounce against the centering springs? You don’t do that with a heli because it will react instantly to every little bounce on the centering springs. The autopilot also has to learn how to be really, really smooth because any sort of aggressive change in attitude with a heli at high speed results in accelerations that are highly undesirable for UAV aircraft.