If I remember it correctly, Martin Lueders (ML modules) has done a polyphonic version of the Befaco EvenVCO for VCV 1.xx.
martin-lueders/Befaco: VCV Rack plugin based on Befaco Eurorack modules (github.com)
Maybe you can use this one and add a polyphonic version of the Percall
?
Or release the Percall as a different module, so that it doesn’t overrwrite the polyphonic module?