This is the second time I've seen this project mentioned on HN. Their white paper is very interesting and aligns closely with my interests but I don't see much on the main site about how to get involved.

Are they using their Matrix server to filter out drive-by/low-effort contributions?

I am the founder of the project. We accept every contribution that solves a problem, even drive-bys. Though they may often sit for a bit as we often merge in batches. If there is something missing, make a PR by all means.

Ask any questions on matrix.