Not much to report today. The Taylor 414CE guitar humidity has increased and now nearly matches the Taylor 356CE. You may recall that the 414CE was allowed to drop to 32% RH in the case study. So, we've seen a gradual increase over the last few days as expected. The reservoir water level is still high, and expected to easily last to summer.
One noteworthy observation is that when the temperature is increased in the morning from 68 deg to around 72 deg, the ambient and Musik Tent humidities drop by about 3% (as reported yesterday) - and they seem to stay at the decreased level the remainder of the day.
UPDATE: Added some fret sprout photos at Pinterest