SilverStripe 4
I have a bunch of DataObjects that behave as pages, similar to the properties in the Lessons. I added the functionality of giving each DataObject a URL, so they can be viewed as a page. The question is, can we use TinyMCE to link to them in an HTMLEditorField?
The site tree link shortcodes are designed for this to link to SiteTree objects, you could create your own shortcode for general DataObjects or subclasses of, but the “insert link” dialogs are all designed to work with pages. It would be interesting to see how extensible they are if you try and configure them for other data sources =)