When Chemaine Hurtado, owner and trainer at Symphony Dressage Stables, came for my most recent lesson, we talked about how Speedy was bridled. She agreed that a double was likely in our future, but not yet. We both agreed on that. I suggested adding a flash, and she agreed.
One of the ways he's been "getting away from me," is by gaping his mouth hugely to avoid the contact, especially when asking for the flying change. He's always opened his mouth a little bit when he's being fussy, but it was never enough for me to clamp his mouth shut with a flash.
I'd rather wait as long as possible before moving to a double bridle, and If I am the only rider doing Third Level without one, it won't bother me in the least. I am sure Speedy won't mind either.