Good day @NicolasCarignani,
It's entirely possible to control the gimbal just like any other motor/rotor passing specific PWM signals. I don't really understand you when you say that PWM is not the same because of accuracy as with PWM you can control the smallest movement the rotor can achieve (if it was at the position it ends up with a 1500 signal, 1499 and 1501 are the smallest changes of rotation the rotor can achieve).
You could take the range the rotors accept (don't know them by heart) and set a proportion so as to pass it degrees or angles and it understands you, but you'll still be working with PWM signals, as you always will (with more or less layers of abstraction).
I might not be understanding you though.