I don't know if there is a formal (internal?) document that guides development, but if there isn't, I think there should be. To avoid situations like this in the future, one of the principles should be "preserving legacy behavior whenever possible".
A bit late to the party, but not really. I was one of two people back in roughly April 2022 who were naive enough to think this was a bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1768070I'm sorry, but if you're adamant about aligning desktop an...