If a lobby was good/fun enough I don't think xp would really matter to the majority of players.
Limited xp was meant to stop boosting which is perfectly well and good for a game at launch but we're at the point now they may as well open the floodgates so people can really test attachments.
The problem with wacky settings is the ammount of stress it puts on the lobby though - In my experience, the more you start tweaking the experience, the laggier it gets
Not sure what you mean about attachments. Those are the one thing you CAN unlock fully in portal/solo. It's only XP and T2/T1 badges that are restricted....
