Add in 1 map downthump

[TouchandFeel]

One of the main points of the Roulette system of queuing is that it provides additional rewards on top of what you would normally get for running the content. The trade-off for the additional rewards is that you agree to be placed into whichever of the instances within the subset determined by the selected Roulette where your role is needed to complete the party.
Being able to opt out of content you don't like or don't want to do in a Roulette destroys that dynamic and the reward structure it is based on, resulting in a lop-sided system that just doles out extra rewards "because ...".

If you want granular control over which content you queue for, just simply select the specific instances that you want to potentially get from the regular lists and queue for them all together. There, you now functionally have what you want, just don't expect to "take" in the form of extra rewards without the potential of a little "give" in return. If you want those extra rewards you have to be open to potentially ending up in content you don't necessarily like but are needed in by other players.

[PyurBlue]

For every 1 person who has a dungeon blocked, 3 will not get it. They would either have to create more backend "queues" for those people, or make the one person who is queued with it blocked in the middle of the 4 who are 1st in the queue to wait and fall back to a different spot on the queue. If the next set is also queued for that dungeon, then it could push them back even more.

One of those things already happens when you queue for a roulette without having all the dungeons in it, which is possible for every roulette except Mentor.

If the added wait time is put on the person opting out of a dungeon it shouldn't be a big deal, especially if the alternative is if they never queued at all and made wait times longer for everyone potentially. It could be that you help more people by increasing the roulette player pool instead of making a smaller player pool cover more content. I can't say if that's actually the case, but it might be. I don't think there would be much of a problem unless 1 or 2 dungeons were blocked by a large portion of the player base. Even if that was the case, you could put restrictions on how a player's dungeon list interacts with the queue. Maybe it could just be a preference instead of an outright block, so that if a player blocks X and no one is queuing for X specifically, X is removed from the list of available dungeons. However if someone was running X for the first time and queued for it, you could potentially be placed in that dungeon anyway.