So, now I had enough of those stupid things spazzing out and bringing the FPS down so much!
Most of the times nothing happens, but sometimes you enter a new cell and this happens automatically: One of the havocked lamps spazzing out with the collision of a wall or ceiling. And sometimes the lamps can even crash the game. It is rare, but it happened already.
The last time for me was in front of Francois Motierre's house.
Another bad experience was with one of my mods, where I placed two of those in a corridor. The mod became unplayable (zero FPS) until I replaced them with a different, static lamp.
I could not find any replacer for this, so I made one.

No Havoc Lamps: This replaces the havocked lamps with static ones. They only have a collision box on the mounting, so they will not get in the way.
Static Training Dummies: Replaces sandbags and wooden dolls with static ones. Collision intact.
Static Cave Roots: Replaces the wobbly roots in caves. They have no collision.