Hi David! :)
Long time no see... sorry, I was actually heavily Lisping around. (Going to send you something in a few weeks - that is IF it works out.)
Now, a suggestion: might you port it to Linux? In such a way that it runs on Termux? See here:
Termux presently does not have a Common Lisp running on it. It has a Scheme, it has Picolisp and things like that.
And while I am at it: any chance for an MS-DOS port? :)
Obviously without the parts chatting with the I/O pins.
Of course, these are just humble proposals, and I understand that microcontrollers are certainly keeping you busy enough, so if you reject these, it would be all too understandable.