Thanks for making this!
I've been using this with the dual loop band and it reduces the pressure on the front of the face very well, making the experience overall much more comfortable despite looking a little silly.
One suggestion for improvement would be to widen the clip and contour it (as well as the battery cage) to a rounded shape so that the battery rests on the back of the head and fits snugly around the head rather than pressing into it at a single point. The clip is definitely noticeable and gets annoying after a little while, and prevents you from leaning back as the plastic presses into your head.
Thanks! I found I had to scale it up a little bit or it was too tight. This worked well for me on a Prusa XL with Prusament PLA.
What fill do you recommend?