Contemplating this through the lens of simply using email and git (ala Linux) to share, review and consume patches, among other things, I can't help but conclude that ultimately this is all totally fucking ridiculous. Sure, it's cool I can send a merge request to another server whatever, but... why are we like this
I like the user experience of forges far more than email clients. (1) It's hard to track the development of a patch in mailing lists unless you actively follow it. Sometimes there will be a v7 patch but it gets buried in the sheer volume of other emails in the list. Sometimes discussions continue in the v6 thread while others occur in v7 so you have to track _both_ threads. And god forbid people changing subject line…
I would add that if you automatize it somehow, then you don't "just use e-mail", but you have a different protocol for it (over email in this case).