I continue to adore this beautiful monster you've put together. I'm ten sessions into a Dracula Dossier campaign, but I'm almost certain Worms is up next.
Anyway! The 'core' mechanics page, 42, seems to have the drawing player settle on when to stop before the And/But gets decided on, but the example of play on 68 has Luz exhibiting narrative control that implies they haven't "locked in the draw" until after the GM settles on what the And/But means. I'd view that as "GM decides, but player has a moment to haggle or *ask* for the power to continue drawing any cards left in their queue." But it's just a little ambiguous.
I dig the phrasing of the card quantity rewrite. "Even Odds" in particular - you say Even, I think Two. Even odds, two cards. It's an intuitive place to center the scale as presented. It feels like you've hit that sweet spot where resolution is intuitive, player or character skill can improve the odds, and min-maxing is maximally minimized. My favorite version yet.... once again coming from someone seeing this from a Theory angle, rather than an active Playtester.