No game company ever did take care of mods when patching. How could they when there is such an abundance of different mods? Of course mods were broken by the patch. And I would not play the game without mods. Two to three days after patching all of my mods at least did work again.
That Patch 6 introduced some new bugs is annoying but was to be expected, given the massive nature of the game and the patch. I hope they removed a lot of the old bugs, for me that was mainly the Error 516 in Act 3 in my first playthrough. Never had a noticable bug in my Honour mode playthrough however.
Anyway, my main criticism of the game is not bugs, or the game stability. I maybe had 3 crashes since start of EA. I had one crash during my whole Honour mode playthrough, with no negative consequences except that I had to replay. BG3 is one of the most solid games I ever played.