FWIW, for smaller drive-by fixes you may press the Edit button directly on a file in some else’s repo.
https://github.com/search?q=is:pr+author:YOURNAME&type=Issue...
Here's how to see all your open PRs:
https://github.com/search?q=is:pr+is:open+author:YOURNAME&ty...
Replace YOURNAME with your GitHub handle, or pick your colleagues names.
Patches require you to share the patch somewhere. Your just sharing the patch to a different interface.
Unless you know something I don't?
I think allowing patches is just a better solution here.