When I equip the main implant shown in the screenshot below my game seems to gain noticible stutters. with other main implants equiped this does not seem to occur. there also seems to be a sort of very vague blurr around my character, especially when moving (I did not manage to get this to show clearly in a screenshot) the stuttering to get seems worse when multiple enemies are nearby. the +2 toughness gives my crusader the absorption milestone from thoughness. The stuttering happens even without enemies or skill use.
edit: just found a main implant that gives +3 thoughness, the same thing happens with that equiped. I took both of those implants, rerolled the +thoughness on one and everything else on the other. on the one that still has +thoughness the stuttering occurs, on the one withouth it the stuttering does not occur.