I made a lot of progress implementing the new stack components today, and preliminary testing shows it all to be working. As I was combing through before making a commit, I found a lot of opportunities to delete and refactor even more code, like removing the Register module along with the Push and Pop traits. I also found that I could eliminate maybe all of the const generics now that a Len64 is coming into I think every stack call; this should simplify things considerably.