Straight forward question. If a player is eliminated in action window 3.1A or 3.2A, does that player still count towards the number of cards to be flipped during staging?

AFAIK, the # of cards revealed is determined at the outset of framework step 3.3. So, while it is known that player elimination during staging does not change the # of encounter cards—e.g., this ruling —I think elimination beforehand means that fewer are revealed.

(BTW, that shorthand of "3.1A" is excellent, and I will adopt it from now on.)