A few examples of existing specific/extreme saves I've profiled and found areas to optimize:
- During heavy combat with 120 + robots (particle slowdown)
- Having 5000+ beacons active at once (tick slowdown)
- Having 66,000+ robots on screen at the same time (Render slowdown)
- Opening a chest with 5000 slots (GUI slowdown)
- Having 50,000 + logistic containers and trying to render the logistic selection for all of them (Render slowdown)
Pushing the game well beyond what it can handle helps to show areas that can easily be improved but don't normally stick out due to how in-frequent they're used in a normal game.
If you're going to post a modded save please include the mods. The mods and save also need to run on 0.12.16.