Stress Test report: Still was able to tank it (lol)
I deconstructed a whole mess of stone brick flooring (always a difficult job) - It never showed more than about 1.4k in the queue, but I got it down to 5 FPS, and 22.1 UPS. Soon as it was done, right back to 60 FPS.
I think it is the visuals that kill it. I move out of the area while it is working, and boom, back to 55-60. move back, tank. Move out, perfect.
This was with multiple actions OFF, for reference. Also had "Hide Paths" ON. Can we get a "Hide little sparkly thing that flies back to turret on deconstruct" to turn ON?
Rebuilding said flooring doesn't seem to have the same impact. Multiple actions on, and in area it stayed up around 30. now that I think about it, it may be because they were low on power, and therefore slowed down. More testing!!
Here's something interesting too: If I simply hover over the UNDO button, with the little window that shows what will be undone (a.k.a. construct all that flooring - resulting in a massive deconstruct command) - the FPS/UPS drops to a very stable 26.6 until I move the mouse off of it.