I would like to define what kind of equipment is not allowed in a party I create.
For example, Polaris is annoying. I don't feel good removing players from my party, just because they use Polaris excessively.
Disallowed equipment should be locked at terminals or subtowns, so it can't be equipped after joining, too.
When the party leader leaves, the restrictions should be removed.
When people try to join and don't have the disallowed equipment equipped, they should be asked, if it's okay for them, to play i a party restricted that way.
When people try to join, but have disallowed equipment equipped, another party has to be found or, if no other party is available, they see a prompt, listing what equipment to change and having the usual "create new party" option.
This is not (yet) a competitive game. I do not want silly noobs blocking my equipment because they don't know how to deal with or work with it.
Polaris can be annoying, yes, but only if the user is an idiot. It's also the best 5* gun and the best line of guns beginning at 2*. Remove the player if they disrupt the party with it.