It would be really nice if this bug that has been around for ages could be fixed.
Fading between masters that contain the same fixtures and are not at full just doesn't work.
When you fade from a master that is at full to a fader @50% and they both have the same fixtures the result is just snap from 100% to 50%. From 50% to 100% it works as should, but if you go from 50% to 85% there is a dip of 6%. Also, from 85% to 50% is pretty much screwed.