RtL campaign: Silver level, Spider Queen & Ascension Plot. The current conquest token level is 283. The OL has razed Frostgate, Dawnmoor, Forge, & Vyneldale; has played the Ascension card "The Harbinger Approaches" and place one comet token at Frostgate.
The Hero party is at " The Fool's Rapids " and, as a result of the comet token, down -1 wound/-1 fatigue. The Hero party has just finished the second dungeon level. However, the Hero party is concerned about what happens when they leave " The Fool's Rapids " dungeon. The Hero party is but two weeks from the Spider Queen's lair and, because of the play of "The Harbinger Approaches," can immediately enter the lair. But, in getting to the lair, the Hero party will go down an additional -5 wounds/-5 fatigue because the OL will be able to play two more comet tokens at Frostgate in that two week period. Return to Tamalir is equally pointless, since all four razed cities are within three weeks of Tamalir, so the Hero party would still be impacted by the comet tokens, to a greater or lesser degree dependent on the placement by the OL.
In order to avoid the emasculating effects of the comet tokens, one intrepid member of the Hero party has suggested, that, after the dungeon's leader has been dispatched, the Hero party not leave the dungeon until the level of conquest tokens have risen to the level required to initiate "The Final Battle." This would be accomplished by the OL recycling the OL deck as much as 106 times in the dungeon (assuming there were no other conquest token generating actions). This intrepid member of the Hero party contends that there is no scripture prohibiting this peculiar strategy. Further, the OL cannot leave the dungeon and once the conquest token level reaches 600, the OL will not be able to place another comet token, and both the OL and the Hero party will start "The Final Battle" at '0' conquest tokens anyhow, so the 100's of conquest tokens gained by the OL in the dungeon will be meaningless.
Is there a rule that forces the Hero party to end the dungeon exploration?
NB : I am a member of the Hero party, but not the intrepid member.