Eventually, maybe for version 2.0.0 it would be nice to be able to start supporting other mod site APIs. Github (or maybe git in general) seems like a reasonable first pick, but eventually stuff like planet minecraft and a few manual websites for optifine and massa.
The syntax could be something like modget add sodium:github or maybe a -r flag that specifies the repo? or both?
https://modrinth.com/ and https://diluv.dev/ should also be supported