[pinum]

I can absolutely sympathise with wanting to avoid to avoid adding support for an outdated system that would be a headache to implement and (I assume) a significant maintenance burden.

But there are a lot of commonjs modules out there, and many/most of them will never migrate to ES modules. It's such a significant downside compared to Parcel that I'm honestly not even inclined to try zwitterion out, let alone get involved with the project by making detailed feature requests.