Playback Fader changing fade times

It would be a nice to be able to set a master fader to proportionally change fade times in a cuelist.
An example of this would be a color cuelist where the fader up would fade the cue in the programmed time, and fader down would bump the next cue in a zero count.
Many times I have a cuelist that is just color with a fader that isn't used (don't always want to use IPCB xfade)and this would really help with busking shows.

I think it would be a more elegant approach than the choose+cuelist rate combo.
Related