This idea also came to me along with the batch of cue selection ideas I posted, but is unrelated and so I thought should get its own post.
As the title says, I think it would be useful to be able to apply parameter level filters to mark flags in cues, just as we can selectively apply blocks to specific parameters. I mark by using Mark (occasionally making us of Low and High Priority) flags on cues, and telling channels almost exclusively to Mark Earliest M. However, sometimes I find that I don't quite have the level of control I want as easily as I would like it, and I end up marking a loud form change where I really didn't want to!
Particularly as we become more and more LED heavy, I think that selectively marking parameters is exceptionally useful. My Lustrs and Colorforce battens can happily mark in time 0, but those TW1s would rather take a little longer to move across the stage and zoom back in to minimum... Therefore, being able to flag a cue as "Mark Colour" as opposed to a full Mark, would be helpful, as I can separate out the noisy form marking into a part with a slightly longer time and not worry about seeing an ugly end of colour fade if the actors skip a line.
Just like discrete timing, when selecting the channels to mark, you can also select parameters. [Channel selection] [Color] [Mark] etc, and [Channel selection] [-] [Color] [Mark] etc, and [Query] [Fixture Type] [Mark] etc should all give you the type of control that you're looking for.