The ban was specifically to hinder the Concorde, so it made sense to base it on supersonic flight rather than noise in case the Concorde would have managed to mitigate its noise level one way or another.

Reference? There was an "Anti-Cordorde Project" [1] but its purpose was to ban all supersonic flight, for environmental reasons. Concorde being the only in regular service, thus the targeted name.

[1] https://en.wikipedia.org/wiki/Anti-Concorde_Project

I don't trust it. They will get approval and then when sonic booms disrupt nature from coast to coast they will say "it's just because the weather/it only affects a small number of people/the 3rd party contractor who supplied the data was wrong, they are gone now/the benefits outweigh the downside/think of all the jobs". Basically they'll say anything other than "oopsie we were wrong, no transonic flight for you".

Bear in mind that despite carefully worded PR, "Boomless cruise" is 1) not guaranteed to be "boomless" 2) is much slower than would make all the rigmarole of supersonic flight worth it even when it is "boomless".

I'm not sure how that matters. A sonic boom in a phenomenon not an SPL reading. The goal should be to have a direct metric for how loud/how much it disturbs things is. "boomless" and "speed" aren't a direct metric. If someone makes a sonic boom that's quiet enough, that's fine too.

I'm not sure how to respond to this because it's really just ignoring what I said entirely (maybe due to a lack of context?) and instead responding to things that I didn't say. "Supersonic for supersonic's sake" makes no sense.