I guess it might not be a good idea to suggest this (not the right time and/or not the right place), but I would have liked to see more modern languages of the same family. Instead of Forth, use Factor (but maybe you mention it as an implementation of Forth) and instead (or in addition to, since is APL has the great Dyalog implementation) of APL use BQN or Uiua (note that it is stack-based too). IMO, in the case of Factor, this is a language that the reader might actually use, contrary to Forth. Anyway that’s cool to see a book about any of those languages.