performance problem on view stems and groups

Per Slack thread, I noticed a pretty obvious degradation in UI performance with the 2.6.7 patch. I tested both as an admin and non-admin. I could tell as a non-admin that the folder expand/collapse UI seemed to be faster due to the StemView addition, but the general UI performance in the main "view" looking at folders and groups and browsing around the system was noticeably slower than previously.

I don't know that it's related to the changes since as an admin that's not supposed to come into play, but it's sluggish regardless of whether I run as admin or not.

I was asked on Slack to get some timings from a Group Save operation, so I'll attach those when I have them, but I actually notice it more viewing than anything else. It feels like the database itself has just slowed down, but this is definitely something that started after the upgrade.