Did you check the "nbr released" notes in the second page ?
This parameter limites the released notes, and then save CPU when using long released patches.
Don't forgettthat audio FM patches are very CPU consumming.
This software is not limited, so you can use every module if you want, use audio FM on oscillator and filter, but nothing is free !
For the same patche : two oscillator, one filter, two envelopes, one mixer and one VCA, the MMV is " only" twice consumming than other common VSTi.
Xavier