Anyone got these Midi FX working: Sostenuto / Monophonic Legato?

As much as I love my Volcas, they do have one problem: No MIDI sustain for droning.
I tried both the MIDI Sostenuto and the MIDI Monophonic Legato plugins, but could not get them to work. Zynthians MIDI log shows my controllers MIDI events - including the CC 64 messages from the pedal, but both plugins are not reacting in any way.
I tried to load them into MOD, but the MIDI routing in MOD does not seem to work.
Is anybody using these plugins with success ?