Sorry if it is already known. I had a break for like 6 years. And still I see on last - tank loses aggro and dps/heal bring boss to fire after pushed tank.

No more.

Tank must do 2 thing to gain back:

1. guard current boss victim

2. then taunt

3. 2-3 seconds later boss is back to tank.

..so well, tested twice on vets. My dps were free to dps First ever time I had full aggro of this boss. Not being like "near by".

P.S. If you just taunt when victim is NOT guarded - taunt gets wasted.

It's part of the boss mechanic there.

The tank gets a kick from the boss that applies a debuff which is taking the tank off the threat table from the boss for its duration. I think the text says something like being ignored as a target. Taunt doesn't change anything about that until the debuff is gone, neither can the tank gain aggro on the droid adds while being under the debuff.

So yes, taunting during that time is wasting the taunt but guard has nothing to do with it, if the tank's threat is still ahead of the other players the boss will turn back to the tank as soon as the debuff falls off, as will he turn on the second in threat as soon as he kicked and debuffed the tank the next time.

The rest of the group simply has to deal with boss aggro for a while, using defensive abilities and drag the boss into the fire to stun him and make him vulnerable (the latter works on the droids as well by the way.). Guard might be helpful for the 5% damage reduction but it doesn't help to deal with that mechanic.