RE: Manwin trainer
A few refinements to think about?
Both ends of the flying lines need to do it right. The launcher should sweep his arm forward, with the model, in about the attitude you want to fly in.
Neither the flier nor the launcher should pull very hard on the lines - you could twang the model into the circle, where you wouldn't have (much?) control.
Also, at the handle, during launch, lead the model like you are whipping it. Actually, you are pretty much whipping it until it settles into smooth flight.
I noticed in operaguy's video a bit of confusion with the feet. (In the second flight, the 2-up training scenes.) Particularly at first, when you're trying to get familiar with flying again, with a new model, etc., tripping over your feet, or worrying too much about them just adds to the tenseness. If you figure on walking backwards in a small circle, you have a plan. It will only change - reversing direction - when you go inverted. But you'll know to expect that. Less confusion, less risk to the model.
As a returnee to CL flying, you probably don't need these thoughts, but they might help you to train a newbie.