I wasn't talking about the OP, the windmills I mentioned were the ones when they were overlooking the abyss. I have watched it quite a while ago. I don't remember every instance of 3dcg, I probably didn't even identify most instance. They take a backseat role, they are easy to miss if not in the foreground.
In the kill la kill documentary (part two about 10 minutes in), They are talking about the CGI cuts in kill la kill. Hiroyuki Imaishi says that he treats the CG animators like every other animators.
From the looks of it, and I could be wrong, for most anime productions the question of should we use CG is answered by "do we have CG staff". The next question in line seems to be "is the director interested". After that the question seems to be "do we have a specific role we want 3dcg to fill", the things in this category would be anime like macross, yuru camp, or ssssgridman, which decided to do most of the mechanical work in 3dcg.
Only then the question goes to "we need X by X how do we do it" or " this will take unrealistically too much time that we cannot afford".
The one example of an anime with the final question would be violet evergarden
After taking a month and a half to make a 45 second preview for Violet evergarden, Somebody in charge stepped their foot down and asked that the typewriters will be done in 3DCG.
Bottom line, these guys are probably credited for minor elements here and there and probably they weren't approached for anything in episode 6.