The Synth Pedalboards - MOD Audio website that the MOD Team has made are only monophonic because the plugin that convert audio to CV is monophonic, and this plugin is mono because CV is mono.
And it doesn’t convert you audio signal to midi, to convert it to a voltage.
To my knowledge there is only a single plugin that can convert your audio signal to midi, this is a beta plugin (you have to allow beta plugin in your Dwarf’s Web interface) called gxtuner from @brummer. Not sure it is polyphonic though…
This thread talk about this recent midi addition to the plugin : Audio to Midi - #9 by brummer