Experts, I need your help: Worldspace edit in CK caused meshes to decombine!

[rcavanah]

I didn't want to use scrap mods on this playthrough, so I removed the remaining shack from Hangman's Alley using the Creation Kit. What I didn't know was that this one little thing would decombine the meshes across the ENTIRE MAP. It's essentially like that old ini version of Spring Cleaning which caused Vertibirds to fly through buildings and caused performance issues in the city.

I tried to undo those worldspace edits by removing the mod, but the meshes remain decombined. Because this is survival mode, I only have three autosaves, and not one of them is from before I deleted the shack. Now I have the vertibird issue, plus some FPS drops like never before. This ruined my game, and I would really love to know if there's any way to fix this issue and reenable the combined meshes. I checked the ini files and it doesn't appear to have caused the combined mesh ini edit, but I could be wrong. This should be easy to replicate, so I would really, really, really appreciate it if somebody could try to do so and see if there's a fix.