Yuletide Feasting Hall is a great skeleton key dungeon as it gives you all three key options to choose from making it so that if you have a mix of lower level wizards and higher level wizards everyone can still do a dungeon at a level they can handle as long as they have the right key. The keys though is where the problem with this comes in. I'm sure it's been said before but in this case it has really become a problem. People start team up for this dungeon but then don't bring ANY of the three keys needed to actually do it. I've noticed this problem when doing team up for skeleton key rooms in other worlds but to me this is a worse offense as it's a limited time dungeon that will only be here for the next few weeks and then everyone has to wait a whole year for it to come back. And the problem is really frequent, out of at least 15 runs I've tried to do so far through team up maybe 5 of them have I actually gotten to do the dungeon as every other time the person who started the team up either didn't have a key or was just plain unwilling to use one. I and I'm sure other players would love it if some kind fix was made so that you cannot start team up for a skeleton key dungeon without having the skeleton key that goes with it in your inventory. Especially for the Yuletide Feasting Hall since again it is a limited time skeleton key dungeon. If not that then another possible solution is if you start team up for a skeleton key room then fail to use a key once inside the dungeon then increase the time penalty used for when you abandon a team up, maybe to 15 minutes. While having the game check inventory for keys would be a better solution, a steep time penalty would at least cut down on people trying to force others to use their keys so that they can get into a dungeon for free rather than farming for keys like other players.
I completely agree OP. The dungeon is already more rare than others, and once it does come around it's a constant struggle just to run the dungeon. Just yesterday I went in with a group that said they didn't have a key, so I port back to my house, get my skeleton key, and unlock stone key Krampus, but as soon as we start the fight all but one of the people bail on me and in the end me and the other person who stayed couldn't beat him thus waisting my key. Things like this make it so that it annoys me that Krampus is a skeleton key boss at all to be honest.