Re: Attn. Tor + All re drying w/c paper flat.
The point made about flattening the paper once it's dry is good, though it's by no meaans certain it would return to the exact original size/shape if it's been unconstrained in the interim. But my own experience in permanently fastening down to a waterproof surface (metal, glass) during the multi-coat process is that,
1. development only from the front, which would then happen, is problematic... it's much preferable (IME) to have the paper wet and developing from both front and back.
2. also, like the power of tree roots to ultimately break concrete, the wet paper WANTS to change size and shape, so unless it's totally fixed in place (as in drymount on metal) it's likely to warp and wrinkle.
(which was why I generally did temporary).
In any event, I doubt the 2-sided tape I mentioned would stick to wet paper. don't think I ever tried it. If it did, however, it might be more easily removed, so in some ways an improvement.