Either you're on vacation or you're not. Vacation mode should apply across all universes.
Also, vacation mode should have a 12h activation timer when unfortunately you should be vulnerable to incoming attacks but cannot launch attacks. Deactivating the timer should place you on 48h cooldown before you can use vmode again.
Vmode should have 24h thaw period where attacks cannot be launched after exiting vmode.
People down voting obviously abuse vacation mode to harm newer players.
Vmode should cost a percentage of your fleet.
Bottom line: vmode should be used for vacation, not by multis who log on occasionally, launch a couple of attacks only to hibernate back in vmode after a few hours. Because that's exactly what is happening.