From what I see in the entity files, I'm pretty sure this is impossible, but I thought I'd ask anyways.

Is there any way to upgrade a capital ship? I'm not talking about the stats, or the model. I'm talking about actually upgrading the entire thing. I.e. version I to version II or III. I have a hack way of doing it, but I would prefer not to take up a build menu slot for each version, in case I want to include more ships later on.

The reason this needs to be done, is basically for the fighters. I'm working on a certain mod in which fighters and bombers will play a huge role. That's not a big deal in itself, but there are about 15-20 different classes of fighters and bombers (I know). Almost all of these will need to be researched to be unlocked. The problem is getting them onto the capital ships. Each race basically has two destroyers capable of deploying fighters. Each destroyer can carry four different types. That's eight total different types. The problem is, that as you tech up, you're stuck with obsolete fighters. Optimally, I would like to be able to upgrade the specific fighters on the ships, but that's definately not possible, so I have to upgrade the destroyers.

Using my current method would take up six capital ship slots per race, so Is there a way I can stack them on the build menu, and only have one of each visible at a time? Or is there another way of doing this?