I’m close to merging a big refactoring so that SourceCred will track “projects” (which may contain multiple GitHub repositories, along with other data) rather than GitHub repositories. It will fix a bunch of bugs, make it easy to add good support for loading whole GitHub orgs, and even leads to net -600 lines of code. 
You can see all the details here: https://github.com/sourcecred/sourcecred/pull/1233