Can you choose not to pay deflect costs, and does this apply differently to triggered abilities versus activated abilities/spells?

Ruling: Deflect is a mandatory additional cost that must be paid during finalization. For triggered abilities, you choose whether to pay deflect as the effect tries to finalize - if you refuse to pay, it fails to finalize and is removed from the chain. For activated abilities and spells, you always have the choice not to play/activate them in the first place, but once you begin the process, deflect becomes a mandatory cost.

Sequence:

• Effects enter the chain as pending
• During cleanup, you declare targets and pay all costs (including deflect) as the effect finalizes
• If you refuse to pay deflect, the effect fails to finalize and is removed from the chain
• If you pay deflect and the effect finalizes, it cannot be removed and will always resolve

Nuances:

• Triggered abilities are unique because in some cases you don't have a choice whether to add them to the chain
• With activated abilities and spells, you can choose not to play/activate them before starting the process
• Once an effect is finalized on the chain, targets cannot be redeclared and the effect cannot be removed unless countered