I doubt that this would have a noticeable influence compared to setting the number of voices to zero. From what was explained by @Mitch in the thread about CPU load, I would guess that being able to set the number of voices to zero is already the feature you’re looking for here.
Disabling effects, especially the reverb, might make more of a difference.
What helped me is that I now see the Synth as something akin to the Elektron Analog Four: a collection of monophonic synths that can be combined for polyphonic stuff. More voices = fewer synths.
Nonetheless, a MIDI engine is a great feature to have.