hello,
i released an updated version of Scheme+ for Racket, fully written with modules.
There is no more needs of external parser (unless for SRFI 105 curly infix which is now in a separate package) as the syntactic job is done with syntax transformers.
Scheme+ and SRFI 105 Curly infix are available by two ways via Github or the Racket Package manager
It's like M*c Do you can consume on site or click and collect the package 
https://github.com/damien-mattei/Scheme-PLUS-for-Racket
https://github.com/damien-mattei/SRFI-105-for-Racket
and still for Racket/R6RS:
https://github.com/damien-mattei/Scheme-PLUS-for-Racket-R6RS
and the same exist for Kawa and Guile too.
Some updated documentation is here:
https://damien-mattei.github.io/Scheme-PLUS-for-Racket/Scheme+io.html
https://github.com/damien-mattei/Scheme-PLUS-for-Racket/blob/main/README.md
Examples can be found in my github repos or under examples/ sub directory.
Do not hesitate to answer about any feedback or ideas about Scheme+.
Regards,
Damien