Looking at your circadian scenes (BTW, I use MBR as the name for my bedroom too) I noticed you have the interval set to 600 or 10 minutes. Does that mean it changes every 10 minutes or just checks the time every 10 minutes? If so, it will not run for the length of time I assume it is intended to. I must be missing part of how it works.
For Circadian - the scene interval is the time in seconds before it wakes up and attempts a circadian change.. It basically checks to see if the brightness or color temp should be altered.. If there is a sufficient delta in either brightness or color temp, it will change it. So if the Scene Interval is very short there really won't be any delta.. An interval of 10 min or more should be just fine.
And I assume the error someone else reported would result from a temp setting outside the range of that bulb? For example, I think the MR16s temp range is 2700-9000. but your scene parameters for MBR circ go down to 1500. I just started the scene so I'll wait to see if I see errors.
In terms of Color Temp range - at this point I am not specifically validating against a mfg spec for each bulb.. But the tunable whites such as your MR16 have a min of 2700K, max of 6500K.. The plugin currently prevents setting a tunable white less than 2700.. I haven't observed any harm to the bulbs if attempting a setting outside of the supported range. They simply ignore it.. For sanity sake though - I recommend just updating the settings based on the bulbs in your group. Most of my bulbs in use are RGBW. I do have 1 Tunable White Kitchen Under Cabinet Light and I have setup a special circadian scene where 2700K is the min.