@thet good idea! That’s something we also discussed. Our plan is to develop all components in plone-react and then find a way to make them re-usable in Plone itself. Bottom line is that developing React components in Plone itself kind of sucks because you are missing all the bells and whistles (Hot Module Reloading, Webpack, etc.) of modern JS development.
For collective.solr we tried to develop the React-based search view in c.solr itself and that did not really work out well.
Therefore I’d suggest that implementing the recurrence widget should have two parts:
- Implement recurrence widget in plone-react
- Make the component reusable
- Use the component in Plone 5.x