I thought of how to get the big carriers as escorts and be able to have more than six. You make a plug-un that makes bays for all the ships, then say you wanted the polaris ravens as escorts. You buy the right bay, the raven, launch the ravens sell the bay, and you can have unlimited escorts in fighter form!!! If you didn't want this cheating to much, you boost the mass needed to get the bay (and the cost) and also the cost for the ships.
(or you could yell at me if its not possible)