The game should let you respond to Generous Plunderer's attack trigger, especially when you have untapped treasures.

Normally when you aren't in full control and don't have any spells you can cast or (non-mana) abilities you can activate, the game autopasses through abilities resolving. This is very frustrating with the card Generous Plunderer specifically, which both creates treasures and creates an attack trigger that counts your artifacts and deals damage to you proportionately. I just lost a game due to the damage from the an opponent attacking with their Plunderer in a board stall because I'd built up a pile of treasures. You shouldn't need to always have full control enabled when your opponent has a Generous Plunderer in play to avoid getting randomly punished for how priority passing works.

Current behavior:
1: Opponent controls a Generous Plunderer, you control an untapped treasure, no other non-land permanents, and no cards in hand
2: Opponent attacks with the Generous Plunderer, it immediately lets the Plunderer trigger resolve.

Desired Behavior:
1: Opponent controls a Generous Plunderer, you control an untapped treasure, no other non-land permanents, and no cards in hand
2: Opponent attacks with the Generous Plunderer, it allows you to sacrifice untapped treasures or allow the attack trigger to resolve.