Still seeing lots of accidental T3 mexes deciding high level ladder games. It will be a problem perpetually since most of these people aren't active regularly so there will always be people coming in that are not adjusted to the change, and do not know it was made.
Similarly, hotbuild seems to have been made a bit more finicky with switching buildings so you can often make accidental air factories or other things.
It is pretty criminal to be constantly changing the UI of a 17 year old game and messing up everyones muscle memory. Many prominent members of the community are inactive for months at a time, and each time they come back there will be different random UI quirks and new stupid features that are enabled by default, along with a new group of UI mods that were broken and have to be replaced.