I just started to write a post about this same thing when I came across this old post and am having the same problem. Any chance that a refresh/recalculate recommended times is available? I just made a few tweaks to my zone settings (soil type, sun/shade, etc.) and wanted to have the Rachio recalculate the recommended times per zone. I do realize the work-around of creating a new schedule is available, but a dedicated button to recalculate would be more practical.
Also, if I change the watering days from the default of "repeating every x days" should the recommended watering times change as well or is that only a feature of Flex? I would think the Fixed schedule would take the frequency of watering into account when recommending watering times along with sun, soil, root depth, etc.