Meaning that they wait until the incursion forms or attaches itself to a level 1 Lair, and the PCs have to go through it first, and have the same problem? Or until the level 2 Lair attaches itself directly to the KoD somewhere potentially completely different, and the players have to hit the incursion one Lair at a time, like whack-a-mole? If they ever even find it again? Then what is the point of having the Lairs be connected to each other,The party has to wait until another incursion happens, and it will, before they can enter the deeper lairs.
Right, but the payers certainly could move to another Lair before the lvl 1 Lair collapses. Unless you view the collapse process as relatively sudden and completely preventing entry into any room that doesn't usher the players back to the surface. But then we have the same problem as above.That is a good question. How I would interpret it is they are not lost in the inner lairs. When the party claims an anchor and the lair collapses, the party within it returns to the Kingdom of Dreams unless they move to another lair before then. Otherwise it would be much harder to play a higher level game. There is no version of Plane Shift in The Nameless Grimoire.