'party' buttons to optional rooms in clockworks levels that require a minimum number of knights to activate (2, 3, 4, clearly indicated on the button), preferably leading to areas that require multiple knights to complete a puzzle
i get that the game is designed to be entirely playable solo, thats cool, but it is an MMO and it is more fun in groups so a simple function that encourages party play but does not impede a solo knight makes a lot of sense to me.
Yes it does punish solo players a bit, preventing them from getting some tasty loot - minor drawback
major drawback
Some players don't associate with anyone outside of their group because randoms are usually meh/okay, somewhat-rarely great, and sometimes downright terrible and you want to throw your computer out.
I'll bet few will leave just because of this, but I'm sure this will contribute if players feel like they have to go with someone else... they have to find a person whether or not they're comfortable being with random people. I feel this would corner some players.