Thanks for your efforts on standardisation!
As a coincidence, I had just stumbled on this (ancient) topic, which was suddenly on my radar since a trivial PR to nixpkgs of mine “blew up” on auto-formatting all-packages.nix (with alejandra, the discovery of which was a coincidence due to it being a default in nvf (nix-wrapper-config-module for nvim.)
What I was a bit surprised about was that the mentioned formatter seemed to have huge interest/momentum at the time (in 2022), I believe mostly in tandem with RFC101, but that I couldn’t easily find historical info on the decision making process after that, that apparently eventually lead to RFC166 “overruling” the former, getting us where we are now.
Don’t get me wrong, I think the fact that there is an official consensus now trumps any other considerations, I’m just interested in the decision making process that lead us here.