How are you planning to close the loophole?
As far as I can see there’s no way to truly close it.
Even if ‘corp hopping’ is deleted people could simply have multiple characters, each in another version of the main war dec corp and cycle between characters as the others are on war cooldown.
No, the best way to avoid war declarations is:
- put no structures up with your group so you can be war immune,
- live away from trade hubs where these war dec players hang out, or
- move out of HS, which makes wars irrelevant
Alternatively group up and fight. Go kill their war headquarters.