What I have noticed is the lag is most definitely linked to the enhanced/tweaked agro of the game. The agro was tweaked in a way to alert nearby enemies to engage, as well as the intended target.
This is part of the game, but the agro has possibly been tweaked incorrectly or excessively, causing severe lag once it is activated. Leading to low fps and super lag.
The targeting of pirate weapons is what appears to be used to start the multiple nearby enemy attack, and that might be the problem. I remember from the POTCO games that my daggers, sword, grenades or staff would not highlight and target nearby enemies while engaged in one enemy at a rerasonable distance, but now since the latest tweak where lag has been prevalent, it does.
In addition to the lag, the enemy will sometimes get locked in repeated, and deadly, finishing moves, such as a loop of blade storms, many times over, so that suddenly a lower level gray tag enemy of say 18 can suddenly become as dangerous as an enemy of red tag level 45, and the pirate is stuck on the first chop skill, over and over again, dealing 15 to 17 attack points and receiving 600+ damage points during the lag-battles. Multiply this enemy attack by say 3 enemies engaged by the agro, and it could get dicey.
Note the screenshot below, where I am already fully engaged in one target enemy, and others suddenly become targeted, (the red target circle) and super lag begins. The other Mercenary was the original target, and as he was being finished off, these 2 became activated.
View attachment 77424
In this shot, I had just finished an enemy, who had stood in front of me and had already taken the loot pouch. As the loot screen goes away, note that the other 2 Mercenaries have already been targeted and eventually both move over to me to engage. Had to use tonic grenades to stop the lag attack from 2 lower level enemies.