You can easily buy those blank panels where the manual seat releases go. I picked them up a couple of years ago on partssouq when I removed everything from my third row.
I wonder if they are using the existing captive nut for the front mount? I used that as a mounting point for a Raingler net.
We've found these retractable covers fairly useless and have removed them from every vehicle we’ve owned that has had them. A dark blanket is more useful for large items and is more versatile.
It might be the same place you are using. See pic below.
My cover is doing an excellent job of taking up space in one of our closets. It's occupying the same spot that one of our old 4Runners cover was stored. Keeps the closet from getting lonely I guess.