I agree. I feel more and more sorry for browser architects every day. It seems now more than ever that modern browsers are just kitchen sinks for spec writers. I'm fully aware some of these spec authors are browser architects themselves, but cut the fat please.

We'll be stuck with these redundant proposals for decades. Webmentions could be a fantastic library on its own, though as previously mentioned, we already have trackbacks. Does it need to be an additional few files in the codebases of Chromium, Firefox, et al.? No.