> [I want to bootstrap] all binaries related to creating a GNU/Linux distribution, such that I can reproduce an exact OS, Racket installation, and Xiden instance. I want a trusted initial state on GNU/Linux.

Seems like the easy path for you is to package Xiden for Guix, and then construct a system definition (using Guix System) that includes Racket and Xiden in its default set of packages, and finally use Guix to build system-images for that target system.

To do this does not require that you can run Racket on the Guile VM. The target system-image doesn't even need to have Guile or Guix installed on it at all; it can just serve as a bootstrapped base and you can build from there to your final desired state.

I'm happy to explain or assist with any part of this process, and I imagine others on this list would be as well.

Designing your own bootstrap and rewriting everything in Racket, or waiting for a suitable Racket-on-Guile implementation, do not seem necessary at all to reach your stated goals. Hope this helps!