But then there's the issue ... "what if a carrier in Open is raided by pirates in Solo?"
I presume (and it's the only way it could work without becoming a cause of complaint), is that Carriers in Open cannot be attacked in Solo, because you would not see the other person's Carrier. Hence why they are Personal carriers, rather than Squadron carriers. The latter would be upset by the Solo/Open issues.
It really does look as though FD have been playing "real games" with these FCs to test out the "what ifs"