Trauma Support with high attack speed inflicting twice as much self damage

I'm not sure if this is working as intended and I'm misunderstanding how PoE's server frames work, but it seems it's possible to take self damage from trauma twice in a single server tick.

For background, I'm working on a trauma stacking build and noticed that I would die to self damage (suicide message in chat) well before my theoretical maximum stacks even if there were no other major sources of damage around. I then did some testing with a lower level gem and after going frame by frame, noticed that I would occasionally take two instances of trauma damage before any amount of recovery kicked in. This got significantly more consistent as I approached the attack speed cap of 30.3 aps.

Here's where I think my misunderstanding might be. As per this comment from Mark, I was under the impression that at an attack skill with no repeats could only hit a maximum of once per server frame. Therefore a hypothetical build with infinite recovery and infinite duration could stack Trauma up until the point where the self damage exceeded their maximum life+es. In practice however, it appears you need to have enough ehp survive roughly double the self damage.

Interestingly, the 'rhythm' of taking double damage changes with the weapon type you use (eg 2hand vs 1hand axe). I have to assume this is due to the different animation timings between them; a 1-handed axe has a noticeably faster 'backswing'. My only theory without being able see what's happening on the server side is that because the attack time isn't consistent, it's possible for the 'frontswing' and 'backswing' to both land in the same server frame which causes two instances of trauma damage without any recovery 'ticks' in between.

If the rule about 1 action per frame is indeed true, it seems inconsistent that it applies to the damage we deal, but not the self damage received from those attacks.

I have been trying to figure out something similar. What defenses are you using? Do you have Strength of Blood or Petrified Blood by chance? Also how much is the attack speed actually?

I noticed that I would die at semi random amounts of stacks (e.g. same setup sometimes dies at 242 stacks and other times 256) but could not find any explanation at all. I did make sure to have all fortify and endu charges at time of death. Leech should have been capped but I can't test that.