Hey everyone.
I'm the one that did the kitbash. Those were WIP renders. At the time I didn't understand that Don didn't want a 3rd warp engine, so the fact that one side is lit and the other isn't is actually accidental on my part.
The final mesh doesn't have the 3rd warp engine, and she's a battlecruiser. She's also got her own registries. Since the kitbash was for personal use, I didn't see much of a problem in doing it, but the ship has a readme file with it anyway, for good measure.
So the 3rd engine being having a lit warp grille on one side only, and it corresponding with old original designs is 100% accidental. Imagine my surprise. My head still hasn't stopped spinning.