Racket is being ported to Chez Scheme. That might solve the batteries included problem at least at the Racket level. However, if you don't like Racket, then I don't know if it will do anything since using Racket's libraries in Chez might be too kludgy to attempt.

https://blog.racket-lang.org/2019/01/racket-on-chez-status.h...

Since you're a Chez fan, I'll also throw in its historical overview in case you missed it. That they had Scheme on 8-bitters really tripped me out. Talented team.

https://www.cs.indiana.edu/~dyb/pubs/hocs.pdf