Thank you for the links. I had seen them.
The first one explains inter alia how to call the player controls and says that they can be customized. The problem is that it provides a link for more info on how to customize and that link leads nowhere (that’s the link I provided in my question).
The 2d one explains how to code a new player UI from scratch, which is not what I want to do if I may avoid it. I just want basically to choose which controls to call and which to hide, something which should be extremely easy if cloudlflare has indeed built customizable controls as they claim (but do not document).
Thanks anywway - any clue still welcome