private repo they commit to and build from
This isn’t possible with Ruby and Mastodon. The only way to distribute the patch is to reveal the changes to the source. FWIW, compiling the fix is still just an obfuscation method, one can still just diff the binaries and see what changed (see: reverse-engineering Windows vulnerabilities in updates).
At best, you can release it with a bunch of unrelated and obfuscating changes, but putting work into doing that is further delaying simply getting the fix released.
I’m pretty obsessive about keeping my car clean, but I also use a vape. It’s no contest: cleaning up after vaping is 100x easier than cleaning up after actual smoke.