Personally I've tanked SEVERAL tankbusters as a WHM on Aetherweaver and survived for keeping the aggro for good first 30 - 60s (or good deal of minutes if the MT somehow drops dead in mid encounter). Full medals & bubble buff also helped immensely to faceroll this.
I do have to kite the bosses as well because it delays auto attacks. Most of time when I still die for tanking on non tanks is because when a tankbuster damage coincides with the next auto attack. Moving out of their auto attack range helps delay this coinciding damage spike.
Let's be real though: unless mechanic forces movement, it's generally the norm that a tank keeps the boss in one spot. When the boss is being kited, that alone should've sent the message across that there's something wrong is going on. -IF- there's at least one tank in the raid who forgets or chooses not to press that one button to steal the aggro to make lives easier for the rest of the raid, they're also (un)intentionally grieving 23 other players. I do have to say though: it's really nice of you to do the actual tank's job on their behalf for however long it is.
I would also kite (while try not to point tankbusters to group) because I'm not well equipped to main tank the encounter! If I want to I'd just go with tank class or went Platebearer/Pure Essence with Lost Incense!









) i naturally helped him as a healer in his dungeons (because insta-queue obviously)


