[jka]

Perhaps less of a code-related comment than you are looking for, but: to make it easier to collect feedback on the architecture/code, I think it might help to add a readme document that summarizes the layout and structure of the repository in a few paragraphs.

Yes, there's a bit of overhead to maintaining that, and it can fall out-of-sync with the code over time.. the key benefit, though, is that it provides useful context for reviewers, a bit like a geographic map does when navigating a new place.

The goal should be to make people feel like they understand more of the purpose and design of the project shortly after they arrive; as a result they'll be able to figure out what aspects of their own experience they can use to help review (and perhaps contribute changes to) the code, and where to go (in terms of files/directories/modules) to best apply that expertise.