AFAIK, a huge part of the point of asking the public to test this is so that they can test it on their code, including private codebases not published to crates.io, so asking everyone to use the same crates would not even be testing what we want to test anymore (especially since it's still limited to 4 threads by default, so a lot of hardware variation won't kick in yet).
The first post of the sister thread basically is that already; it lists 10 shell commands that do all of these steps: Help test parallel rustc!