No need for that. Just install the VSCode GitHub extension and you can just directly open them. It even supports comments.
Hell even if you don't use VSCode there are much better options than messing around with patch files.
When I read
> No need for that.
I generally expect a less complex solution, it seems like your is more complex (easiness is arguable though)
VSCode is not a “given” - I certainly don’t use, or ever intend to use, it.
Patch files are excellent for small diffs at a glance. Sure, I can also `git remote add coworker ssh://fork.url` and `git diff origin/main..coworker/branch`, and that would even let me use Difftastic (!), but the patch is entirely reasonable for quick glances of small branch diffs.