This instance has such a bad design, I'm sorry for the people who designed it but that's how it is. It feels like an individual instance until the MVP room (which is really just a DPS statcheck). Before the MVP room I don't even see like half of my party, it DOES NOT feel like a party instance at all.
There are a lot of issues with this instance. If not for the crazy amount of zeny I can generate from farming the instance daily I would never touch this instance, at all. As compared to other servers I've played in (Nova) I would still keep doing instances regardless of the zeny I could generate at the end of the run, as long as I had fun playing with my friends or even with random players.
Which is another issue for this instance. Considering that this instance has a lot of things that can go wrong with an unorganized party, it's very exclusive for only a small group of players. I could never see myself recruiting a random player for this instance unless I'm REALLY REALLY REALLY REALLY REALLY desperate. I understand the importance of having an organized party but this just feels extreme, having a 1-day CD isn't helping either. Once you F up the run, you won't have another chance until the next reset OR unless you have multiple characters.
Which brings me to my other suggestion, custom instances should have no CD, people should be able to run it as much as they want/can without worrying about the CD if they fail or F up the run. This would also remove the exclusivity of organizing parties for this and future custom instances.