How to make frint work with custom elements or custom element lib (lit-html, atomico etc)?

I'm trying to make frintjs work with [atomico](https://github.com/atomicojs/atomico/issues/27) which uses reactive custom elements (aka web components) and seems a more modern and natural fit for frintjs.

Would much appreciate some advice for how to make a frint adapter for a custom elements library.
Does the component have to be a class? The modern way seems to be a more functional approach, such as with React 16 using hooks. Atomico also uses hooks.

Start by reviewing frint's adapter model and the linked Atomico issue, then compare their assumptions about class-based components with Atomico's functional, hook-based custom elements. Determine whether an adapter is feasible and document the required integration path or a concrete blocker; the report names no files or tests.

Written by the indexing model from the issue text.