I am sorry. 
I do want to thank you for enabling this discussion in the first place. I have learned a lot even when the discussions get tough. I know you put a lot of effort into the PR, and didn’t have to come here in the first place, and didn’t have to come back to revisit it. I am also sorry to @nightpool – I know we often see things differently, and I genuinely appreciate your persistent willingness to push back against me.
I’m not intending to block y’all doing what you need to do to fix the problems you’re seeing day-to-day. I just wanted to be sure objections were heard, they were recognized, even if not addressed. I am sorry that I got a bit upset around this, I do think y’all recognized them but in the moment it didn’t feel that way.
In that spirit, I don’t think I have any new objections, and don’t feel the need to revisit old ones. Feel empowered to carry on as you see fit.
Whichever course you choose (submitting the PR as-is with the HTTP header, reverting back to the original proposal, or something else), I hope I haven’t soured the thread so badly that y’all aren’t considering trying out a FEP. Since you’re breaking new ground it would be nice if it existed as a FEP so others could use your solution in an interoperable way.