Would love to see a system like this in place. As of now, it feels discouraging to grind together, while i usually like to spend time with my friends in games. Mirumok and other party-grind spots worked fine, but they are few.
How about PA makes a loot pool option when grinding in a party, and all loot goes into the pool.
At anytime during the party process, the leader can distribute loot from the party pool.
Sounds like a nice idea, but needs a solution if the party leader or everyone goes offline without distributing the loot-pool. Also the system shouldn't allow the leader to distribute the loot themselves (abuse, albeit probably rare). So if the lootpool can be distributed after the party set their options as OP mentioned, that would be fine. However it would be easier if distribution happened automatically then, no? Hmm.