Sqeenix you need to get on this now. You advertise Odin and Behemoth as part of great end game challenges, and yet so far the only challenge has been seeing them. I would propose several changes in addition to adjusting load priority.
1) just as if you don't lvl sync down you cant dmg a mob, anyone under lvl 50 should not be able to dmg Odin or Behemoth
2) as stated by many others in this thread, non party member pc should have the lowest load priority
3) If you can't see the boss, and therein can not do dmg to him, he should not be able to do dmg to you.

Plz and thank you. this is much more important use of resources than an AFK kicker.