2023-11-10 : If you can't legally choose a mode because all three have been chosen that turn, that instance of the ability is removed from the stack with no effect.

2023-11-10 : If you somehow control two or more Breeches, Eager Pillager, track which modes have been chosen each turn for each one's ability separately.

2023-11-10 : You pay all costs and follow all normal timing rules for cards played this way. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty.