This is just my thought and I wonder what do you think.
I think it has been confirmed that Kralkatorrik is largest of the Dragons with only Jormag being close to him, but Dragons change over time as we saw with Primordus ( GW1 and GW2 difference) so it’s possible that he’s even bigger now.
My thought is what if we had a map in Crystal Desert that takes place entirely on Kralkatorrik back. Say maybe we or Balth did something to him that left him grounded, with a map wide Meta Event similar to Dragon Stand, but in this case Kralkatorrik would stir during meta event so entire map would be changing for the duration of the event.