Ohana booking

What would be the best time to get a reservation for dinner at Ohana to try and catch the fireworks at Magic Kingdom?

Best time? Get an 8:30-8:40 reservation, and check in for it immediately upon being eligible to: 30 minutes in advance of the reservation time.

Are you asking about watching them at MK or from the Poly?

From the Poly but never eaten dinner at Ohana before only breakfast