I'll not vote since my answer is in between and I am still evaluating this since it is a new way of doing the cover.
I am good with it because at least, there will not be any problems on waiting for lines and finding covers. Since, basically, the waiting for lines is one of the problems. I encounter it frequently in my own project so I know how it feels. Also, with this kind of way, the mixer can choose which lines to give each member, since sometimes, we can't avoid it, at some parts, we sing too loud which causes distortions on the recording, making some popping sounds. So in this case, we can eliminate this.
Although...
at the time being, you can get fast covers in the dubbing group in facebook, which made it faster for me to deal with covers. And seeing color-codes makes the dubber a bit inspired if they see they have solo lines and can give it their all to that line. On the down side, if the member sees she has less solo lines, it will also discourage her.