In Rime we had a lot of performance problems, we didn't know what was going on since we paid for the change to an engine that we didn't have much control over. Objects were disappearing, there were more calls than usual, we didn't know a lot of things, so I created this blueprint called BP_ActorFinder, which helped us as we learned as we went along. 

It was much easier to find some mistakes that we were making during the development of the maps. This helped us to find out which object had what problem.

- If an object appeared at 0,0,0,0.
- If an object had more than X materials.
- If it was rescaled.
- If it was not visible in game.
- If it had the mesh set to null.
- If it had the Tick activated or not by default.
- Etc...

It helped to find and correct many small problems that had accumulated over time.