I never digged into it so being honest, I don't even know how it works. But my impression is that you need to report your work every X months, is that correct? 

My biggest concern is that I like to have the freedom to dissapear for 3 months and come back to whatever random project I find. 

 3-page Every quarter. They are flexible, but it's about how much you deliver in the months you are working. Apply doesn't hurt.