Can you float energy from runes at the same time as paying the power cost for Bullet Time after it resolves?

Ruling: Yes, you can activate "Add" abilities (such as floating energy from runes) when paying a cost for a spell like Bullet Time.

Nuances:

• The Add abilities must be Reaction speed to be used during cost payment
• Runes are innately Reaction speed for both their abilities
• There is only one known Add effect that isn't Reaction speed