I would like to see a way to calibrate what Kelvin a light is at its coldest/mid/warmest setting to better match the whole room. In my livingroom I have 2 different types of RGBW-bulbs with similar range, but I also have a couple of golden coloured filament bulbs that goes really warm white (almost orange) they do go about as cold as the others and at daylight temperature they are quite close.
I think a good way is to point the light to a white card and let my mirrorless camera do a white balance and just input that as the values for this bulb as how low, how high and a midpoint in Kelvin so when I set the colour temperature of the room the lights always match (as long as they are all in range) I would still want to set it to 2000K even if one of the lights wont go lower than 3000K