The more you add to the back the heavier the limbs will be and that will decrease speed and add hand shock. If you add snake skins or rawhide you will be able to see the texture of the dry wall tape through the backing. I guess you could spray paing the back to cover the FG tape.
I never understood the dry wall tape backing thing. There are way better options out there for bow backings, IMO, than fiberglass dry wall tape. I would rather have something that would give a full, even coverage than a mesh type covering.