Custom graphs with the v1-v12 values

I have an idea that could be useful for future updates: Allow the users to be able to define custom graphs (lines, pies, etc) with the data available in the 12 standard and custom values as well as calculated values from those 12. The calculated values not to make use of the v1-v12, to be extra (like vc1, vc2…). These calculated values do not need to take any more database space, since are calculated from the existing ones.

Thank you,