Hi
A couple of things I found while testing.
Your Sims die whenever you change a skill on your bar, any skill.
I’ve also found on random occasions when doing normal rifts and or bounties that your sims just vanish and you have to recast them. This is not when taking damage in battle. They can be up, you go to town your portal to next bounty then suddenly they are gone for nothing.
This has happened in GR’s too without taking damage.
It is pointless to just have no cooldown on sims when you die, you actually need it when they proc the cheat death rune because if you proc the rune early in GR you are running around like a headless chicken for up to 2 mins waiting for the cooldown. Now you can’t make sims have no cooldown on proc because you would just be able to recast or numlock sim and you would prevent yourself from actually using final service. Let final service proc before sims rune proc and then refund the cooldown. This way you can recast and battle on but wil have no final service for 60 sec which means your next sim death will cause your death.