If I had the opportunity to ask CO for one thing, I currently would ask them to make it possible for me to grant, to my secondary-account toons, permanent access to my primary account's hideout. I can make them member of my primary's SG, but I have to "manually" get them into the hideout each time.
Of course, that would make buying the secondary a separate hideout unnecessary, but I could live with that. One supergroup, one hideout. Perfectly rational.