The secondary hull is bulky and adds a substantial chunk of mass to the ship, and the extra-large deflector dish garners a few sceptical looks. Fundamentally it's just a supercharged Type-1 deflector with a larger emission profile, but you may need to smooth out some technical difficulties when it's actually put through its paces. Or you might be pleasantly surprised. Hope springs eternal.
The final major step for the spaceframe and final shape of the ship is the nacelles. While the overall shape and internal configurations are all settled, where precisely to mount them is an ongoing debate. There are two options with significant internal support, each playing to a different strength. The first is to have the nacelles in line with halfway to the edge of the saucer. They would be positioned closer to the center of mass and a little higher than standard to produce a more compact warp field for high cruise velocities.
Option number two has more in common with the Stingray, with the nacelles in a racing configuration near the edges of the saucer. The distended warp field will lend itself towards high-energy configurations that take advantage of that natural instability, pushing the maximum warp factor the engines can produce up the scale.
The only risk associated with the decision here is the possibility the ship might not reach Warp 5 right out of spacedock. While the engineers are confident that the engine is capable of Warp 5, they reiterate that some work may have to be done progressively once the ship is out and in service. The most pessimistic of the bunch, however, grumbles that it needs all the help it can get or they'll be calling it the "Warp 4.9 engine" for the first few years of operation. Strictly speaking it isn't your concern how well a single piece of equipment performs, and you have already helped push the envelope by integrating the new Type 1-B warp coils. Nobody can say you didn't contribute. If higher cruise is considered more useful, you can't be blamed for the shortcomings of another department.