Did I say that?
It took me a couple years to come to terms with the benefits of a slightly larger deflector
For those that have it, a think a same size deflector is fine, but if someone's building from scratch, I now recommend a larger deflector.
LBEs tend to have directional air flow- up the back and then over the pizza and out the front, and a round (rather than a deca) kiln shelf deflector helps to close off the front and create an opening in the back. That being said, there are those that have taken a more centralized rather than an offset approach and who I think might have been successful (it's been a long thread).
I believe the 18" baking stone on top of the 19" deca is the answer (with air between- air is good!
) but, before you go shopping for an 18" stone, I'd see what the 15" does.
It's tough. If you were happy with 4 minute NY bakes, then things like the airflow with the deca probably wouldn't matter much. Since you're talking about Caputo and referencing Neo in your profile, then you have absolutely no margin for error.
Speaking of Neo... aluminum starts being problematic above 1000, and, LBEs, especially LBEs attempting Neo, can definitely hit that. It makes things so much harder when you can't use aluminum for the ceiling, but if you're shooting for sub 2 minutes, I'd avoid it.