i do for layering, I think foam on foam with gorilla glue is stronger than paper on paper with hot glue. In ft plans I'll keep it mostly on except sometimes inside the wing airfoil. Depends on the planes really. I like using different foamboards as well, for example Elmer's is much heavierbut more readily available here in canada. The paper is thick so it's heavy, however it holds paint well and is much stronger. I'll build spars and fuselage with elmers, sometimes depapering the inside. I'll use Adams for wings.
The paper adds strength, use your judgement when it's worth depapering or not.