[the__alchemist]

Great point. Using Liftoff and similar is a game changer. Flying in acro mode is something where you will crash repeatedly at first. (At least I did... in Liftoff thankfully!) Then after a relatively short time, the controls will be intuitive, it will feel easy, and you don't forget. Like riding a bicyle is a perfect analogy.

I think 20 hours is excessive. I'd say 30 mins to 2 hours is fine, depending on the user. The most dramatic learning will happen in the first 10 mins or so.

[meheleventyone]

Depends on what you intend to do IRL if it's just fly around then a couple of hours in acro will get people up to the point where they can bimble about and sort of land but will easily get way out of their depth.