Tank IDENTITY

[ItsUrBoi]

Provoke could easily give a further bump of temporary Enmity and thereby remove any need whatsoever for Shirk (not that there's a need even now).

What? I don't think you know how this works. You do need to shirk all the time when executing a tank swap.
To argument why, let's say I am a DRK and my PLD co tank wants to taunt for a tank swap mechanic. He taunts, and we are now very close in aggro, but he has a slight edge. If I do not shirk, and my burst is coming up, I will surpass him in aggro and you know what's gonna happen? The boss will switch from tank to tank, both tanks fighting for aggro. Shirk is absolutely needed when swapping. Turning tank stance off and on could be a replacement for that, but you are still generating aggro, just not as much, and doesn't fully solve the issue either because in some mechanics you will want to swap twice ( OT taunt , MT shirk -> mechanic happens -> MT taunt, OT shirk , so if the MT turned stance off, how will he provoke effectively, since the aggro provoke gives is increased by tank stance )

[Shurrikhan]

You do need to shirk all the time when executing a tank swap.

The (former) MT can literally just turn off tank stance before swapping out. It's 10x bonus enmity, and tanks already do almost two-thirds the damage of DPS. Keeping a lead over the dps will not be dependent on using Shirk nor on keeping up tank stance for even the couple seconds before swapping out.

It's an oGCD toggle, mate.

[ItsUrBoi]

Read my whole answer before and think again...

The problem is not being over taken by dps, its by the other tank. And yes its just a toggle but most tank swaps usually happen twice.
Also very often due to tank dps ( ex: DRK + any tank except GNB in Endwalker content ) you will have to shirk even when not swapping because you are over taking the main tank in aggro.

[Shurrikhan]

Read my whole answer before and think again...

The problem is not being over taken by dps, its by the other tank. And yes its just a toggle but most tank swaps usually happen twice.
Also very often due to tank dps ( ex: DRK + any tank except GNB in Endwalker content ) you will have to shirk even when not swapping because you are over taking the main tank in aggro.

Again. You will not overtake the MT in aggro. If you just. Turn off tank stance. Toggle it off just before you swap out and turn it on again only before Voking back in.

It's an oGCD toggle, mate. One can both turn it off before swapping out and back on, without any cost, before swapping back in.

If you're taking threat off your MT when you don't intend to, there's a much simpler solution than Shirk: turn your damn stance off, OT, until you're swapping in. You only, at most, need 2nd highest threat, which at 10x enmity doesn't take much stance uptime.