I was able to squeeze another 1/2mm of thickness off the design by making the drive wheel and cover tape wheel turn at equal rates. I made up for this by making the cover tape reel slightly larger than the drive wheel (so the clutch still slips). Its got a Buddha belly now.
11.5mm of width is just .5mm more than the reel the 8mm tapes come on. I'm done making it thinner.
I have a new idea for how to handle the cover slip the components show through. I think you're gonna like it.