Link RGB Mixer Sliders without Averaging

**Feature Request** In the Color Engine Tab/Module > RGB Mixer sliders I'd like to be able to lock/link the sliders to adjust at the same time (Black or White Point) but without it AVERAGING VALUES, which is neat but Id suggest a FIRST BEHAVIOR-STATE > locking the Values AS THEY ARE at there given position relative to each other an allow the linked movement lever behavior, a SECOND CLICK to the Lock/Link would trigger the AVERAGING. **Use Case** It is common to have different values for the RGB Mixer Black & White Point and by allowing a linked movement but maintaining different values without averaging one can maintain the characteristics/look of the settings. As it is now If I want to maintain their relative different values to each other but lower or augment them all, I have to do this manually one by one because the LOCK doesn't allow locking the values without changing their values, averaging them. By adding a first or second LOCK state would be considerably quicker/simpler.