I've just been re-reading Simon Aronson's Try The Impossible and was struck by the cleverness of his undo influence. I tried out Prior Commitment and was as impressed that it worked as the person I tried it on.
You've basically got a very deceptive way of controlling two cut-to selections to predetermined positions in the pack. I like spelling and 'placementy' type of effects and was wondering about other applications for this type of principle.
Something that may put some people off is the necessity to spread through the deck after the cards have been selected. Weighing up the handling, you might decide that there are simpler procedures that negate this step, with an equal feeling of the selections being lost in the deck - but it's so clever, I'm sure there must be loads of other effects where this would come into its own.
One thing that Simon touches on is the idea of crimping the two keycards, meaning that you could have two cards cut to and replaced before cutting the deck into thirds and replacing those thirds in a different (the required) order. Following this with a riffle shuffle that retained the critical positions seems like a very deceptive way of fixing whilst seemingly losing two selected cards.
It also seems that you could alter the positions of the two keys before the selections so, for example, one of the selections could be found by spelling the spectator's name etc. I enjoyed 'Twice as hard' but (and I might be alone here) I think that a double ACAAN might actually be less strong than a single revelation. And if you were doing a single revelation with the same handling,you could have the card named and, if we're spreading, simply cut it to the right position!
Notwithstanding, there's surely a good application in this type of effect - perhaps combined with a further mathematical principal/stack. Has anybody else explored this?