Installed the screen onto the base frame, and the motorized mask fabric.

I ran into some challenges, I have a few ideas for better ways to attach the fabric to keep it nice and tight, but I think the additional effort may not be worth it, pretty happy with the results.

In short I think a strap/webbing or some sort of guide wire above and below the mask, but not rolling up into the mask fabric, might give some attachment point to keep the fabric tighter and avoid any sagging. You'd need some sort of channel or attachment on your rollers to keep the guide strap rolling up in place rather than spiraling and sagging as it rolls up.