As for the deflection crystal, that's something that the vertical intermixer/warp core can, but does not necessarily have to, connect to?
If it's functioning as a 'warp field symmetry' doohickey, I'd say it doesn't have to. If it's doubling as a power converter for the impulse engines, I'd say it has to at least have a line running to it. I again prefer Probert's connected configuration for the sake of 'respect of intent.'
Well, if you're referring to the symmetrical warp governor from the NX-01, per the the Drex Files blog
, the idea was that that had been obsoleted shortly before "The Cage" by improvements in the basic technology allowing them to natively
generate symmetrical warp fields. Ergo, there's no way the E-refit or E-A should need one.