Hello, I was using this mod with the Strategy Mortar turret and started having massive performance issues when raids attack, having my FPS drop to 10. Raid size was also set to 3 and evolution was approximately at 0.65. The performance issue started when the waves began getting much bigger.

With further testing, I concluded that when the mortar turrets fire from far away at the incoming raid, the performance drops at the same time as the shells from the mortars hit the biter wave. After the biters are hit, they kind of get stuck and stop moving, but as soon as the effects of the shells stop—such as fires from fire shells—the performance goes back to normal and the biters continue moving towards the attack target location. So, the biters don't seem to aggro when they are hit with the mortar turrets, at least from far away.

It seems like the biters don't know what attacked them when they are hit from that far away or just with the mortar turrets. Not sure if the raid wave gets messed up if attacked from far away. Also, in the editor, if placing turrets in the middle of the wave, they aggro to it and the performance goes back to normal until it gets destroyed and the biters deaggro.

So, it seems like the biters in the raid wave are unable to aggro the attacking mortar turrets and get stuck in some loop trying to figure out what's attacking them, causing massive lag. This issue is technically the cause of another mod and I could very well just stop using it, but I just liked that it adds balanced combat turrets. But I also enjoy this mod very much and especially the raids that attack outside of pollution attacks. So, could there be a solution to the issue through this mod?

With more testing, the performance drops happen also with vanilla legendary flamethrower turrets. Any other turret with a long range also cause small stutters the moments they hit the raid wave from far away before the biters are aggroed. Fire on the ground just causes the most lag.

Thank you for the detailed report and the extra tests.
I could not reproduce the lag yet. I sent a raid of 1950 biters past long-range
flamethrower turrets and a copy of the mortar fire shell. The slowest game update
took 10 ms, so the game stayed at 60 UPS. My test used Factorio 2.0.
Smart Enemies runs no script when a raid biter takes damage. After a raid leaves,
the mod gives it no more commands. The stop that you see is the game's own unit
behavior. In my test, a group turned to attack a turret within about 50 tiles and
stopped its walk. A group that could not reach the turret stayed there until it died.
Please send me this information:
1. Your Factorio version and your Smart Enemies version.
2. Press F4 and turn on show-fps and show-time-usage. Take a screenshot while the lag
occurs. This shows if the UPS drops or only the FPS, and which part uses the time.
3. The mortar type (normal or heavy), the shell types, and the distance to the wave.
4. Your mod list, or a save from just before a raid arrives.

While checking mod versions, I realized that smart Enemies was on version 10.9.5 and not on the newest version. After updating the performance issues were fixed. The situation is weird, because I always update mods through the ingame updater, which now for some reason wasn't showing any available updates and needed to be manually updated. Sorry for the inconvenience.

No inconvenience happend :D If its running i am happy :D