That I don't know, but the s7 author, Bill Schottstaedt (who I will ping about this) is very helpful on the email list and is deeply, deeply knowledgeable about Lisp, so you could definitely ask there!

https://ccrma-mail.stanford.edu/mailman/listinfo/cmdist

In my context, I have rigged up a REPL in Max, so I wind up using that instead. (Which is freaking awesome, because I can script all of Max from my vim buffers.)