It might affect performance. If I understand how detail boxes work it will only affect performance when you are physically inside the bay. Given the style it is made in you won't even notice the geometry change until you round the entrance into the bay.
More pics of the ship:
A size comparison between a 20 meter long Blizzard Fighter and the secondary armament of the Typhoon. The twin linear plasma cannons are nothing to laugh at, and those are only secondary weapon arrays.

Another size comparison, this time the primary weapon, the Beam Cannon. If I remember the measures, this cannon is 600 meters long D:

I said before that the bay opening is BIG. ANd this is the truth:
