On top of the constant errors when loading or editing a batch (happened every time with the old tool too) now it's not even doing it's one and only job: to change listings in bulk.
I have tried to remove all promoted listings multiple times. Pretty easy, right? Check all the boxes, bring up the drop down in the menu and hit "Stop Promoting". Everything looks correct (except for the random 76 items that couldn't update for some random reason), I verified all the listings do indeed show no promoting. Save the batch and go back to the listing page and not a single one has been changed. Funny that.
