A few observations after reading the last five pages of posts.
My plan for the "Evil Twins" fight was to save the version of each PC as they were when they first entered the Dreamlands as a separate file on Herolab, then import both versions for the final battle. The program really makes this kind of thing very easy to do, though I do like the idea of alternate build versions of the PCs.
I had been wondering in the back of my mind, "Did the PCs lose only their memories, or also their prior class levels?" I did that once to a starting PC in a home campaign who asked to start the game as an amnesiac. It turned out he lost his memories due to severe trauma from being level drained by vampires down to level 1, but that came out many sessions later. But I hadn't considered alternate class builds until I read this thread.
Regarding motivation to enter the Dreamlands/regain their memories...while I don't blame any PCs or players for not wanting to remember what the PCs had done in the past, it's also a dodge to avoid dealing with the consequences of their prior behavior. In a more practical sense, it means they will keep having problematic Thrushmore-like encounters without being forewarned by their memories. It also gives them no way to know what they did wrong, or how to make up for it, or to whom. So there are good arguments in favor of regaining their memories, however unpleasant they may be to live with.
But just to be safe, I will remove the note about Lowls' next stop from their handout.