Except that you give up your chance to drive a Super Yamato and an Amagi, plus you
would have to raise a CV crew from scratch or buy a high-level one just to play the
Shinano. In either case you're a hell of a lot better off just raising a second BO and
going up one of the CV branches with it.

Wow nice bb line converges to cv line

Yes, but that's a one-way street there, it doesn't work the other way. For reference,
SDE decided to do that because the Shinano was technically a Yamato hull that was
converted to become a support carrier.

I believe you can choose shinano if you go yammy..?