Can you play Catalyst of Aeons while you have all 12 runes up, and is there any benefit to floating a rune first?

Ruling: You can play Catalyst of Aeons at 12 runes and still get the draw effect. However, it is optimal to float energy/power from a rune first, then play Catalyst - you still get the draw and get your rune back.

Sequence:

• Float energy/power from a rune (going to 11 runes)
• Play Catalyst of Aeons
• Channel 1 rune back and draw a card

Nuances:

• Playing Catalyst at 12 runes works, but you miss out on the floating benefit since you cannot channel back above 12 runes