Working in separate modules for development, and then snapshotting copies of the files in a master repository, seems a good compromise if you're trying to have one-repo-to-rule-them-all in a known good state for deployment.
But in terms of breaking it all the way to one script per repository, maybe that's excessive, and it should just be r3c-zip and r3c-pdf, where common files pick one home or the other.
I'm still using the super-basic "just write expressions that return true" format, as with Saphirion tests.
Though one interesting concept you might have missed out on is that the Ren-C test suite is now a client of the "make your own module" syntax, in that it isolates all test files into modules...and then within the file everything in a BLOCK! is made into a module
So due to Sea of Words you can run all the thousands of tests making hundreds of these modules, and nothing winds up added to the user context.
But that's really the only area of innovation there. ISSUE! and URL! are allowed as literals to serve as comments without needing semicolons.