AI5 waited till turn 12 (or so) to play first 3 pillars. Had done draw/discard for each previous turn.
(Yes, I'm playing a pest deck so you can't verify with a quanta count, but I forgot to do screenshot before this turn.)
EDIT: AI5 not playing creatures at all x4 matches so far waiting several turns to play first creature even with double-digit quanta stored up.