We could use a Preferred/Blocked player list for DF.

[MoraClaret]

There is not much simple and elegant way to do this, the logistics is just complicated especially for larger raids where they need to check for all (24?) players to make sure no one is on anyone's blist. This would make some of the match up very difficult.

This is also very discouraging to new players, if they mess up on their first time, they get blisted.

Like I mentioned previously, it might be required to compromise and make people on your blacklist simply less likely to be matched up with you rather then not at all.

You're also kind of using the most extreme case (CT) to nay-say this idea. Even if it was only used for 4 or 8 member parties it would be beneficial.