I could not find clarification in the rule book specifically stating these circumstances are still in effect or not during your battle with the ancient one:
1-Do you continue to resolve "at midnight" effects on adventure cards in play during your battle with the ancient one? for example we had in play " horrible visions" which tells you to add 2 doom tokens to the doom track every midnight.
2-similarily do locked dice on adventure cards in play remain locked?
3-it does state that if you are devoured due to complete loss of sanity, stamina or both, a doom token is added to the doom track. is this still the case when you are devoured during the final battle(which isnt necessarily due to sanity or stamina loss) ?
and a final thought, we played retaining all those consequences in effect and still easily defeated our ancient one only having to draw 2 additional investigators, leaving of course 12 still in the draw pile. that seems to make all the time(well over an hour)and effort spent trying to prevent the ancient one from awakening a waste. looking over the ancient one cards, its clear some are certainly easier than others, but being able to draw a new investigator out of a stack of 16, even removing from play permanently devoured investigators seems to cheapen the final battle when it occurs.