Can a field widget rely on PortableTextEditor, onEditorReady and emdashPortableTextKey?

[esalazarv]

A custom field widget, built following "Custom field widgets" in the React admin extensions guide, can wrap the admin's own rich text editor for a portableText field to add behaviour such as inline highlights. Doing that relies on exports that the docs do not cover:

• PortableTextEditor and PortableTextEditorProps from @emdash-cms/admin.
• The onEditorReady prop, which hands over the TipTap editor (and null on unmount). The widget would call registerPlugin, unregisterPlugin, on/off for update and transaction, view.dispatch, and the setTextSelection and scrollIntoView commands.
• The emdashPortableTextKey node attribute, which maps editor blocks back to Portable Text _key values.
• API_BASE from @emdash-cms/admin, used to build a plugin route URL.

Are these public API that plugins can rely on across minor versions? If they are internal, is there a supported way for a field widget to reuse the host's rich text editor?