I was just mulling over set today, so this is timely for me. I disagree ever so slightly with El D on one thing, which is the curability of set. Set is the deformation - specifically compression - of the wood cells in the belly. When we bend wood with heat, to add reflex, we are increasing the plasticity of the wood in order to stretch the belly cells. Then the hardening effect of the heat (hopefully) prevents the cells from reverting to their previous shape. So for me, I don't see a difference between correcting set with heat, and inducing reflex. The cells probably have more structural damage in the correction scenario, and are therefore more likely to relapse, but I doubt it's "set" in stone, lol. (Pun intended.)
*This reply in no way is intended as investment advice, it is presented for information purposes only* lol.