That's actually something that can already be done from the MCU command line if a fancy user interface for the feature isn't needed. The command line offers access to the bfgminer settings for frequency adjustment + voltage and fan control. Since it's a Linux distribution, cron can be used for scheduling events based on day or time preference.
How does one access the command line of an Apollo?
As you can probably guess from the lack of such details from the first page instruction posts, this isn't officially supported and falls to the category of "do only if you know what you are doing": ssh with username 'futurebit' to the Apollo IP, default port 22 using password 'futurebit'.