@insyncwithfoo thanks! This was very helpful. I think the documentation about descriptionDirectoryName could be improved (you mentioning the “child directory of” saved me some time).
I ended up setting a description and removing the IntentionPreviewInfo.EMPTY override. Now there is a simple HTML render, which is good enough 
Problems left
However, I’m still stuck with:
- Understanding how to properly setup a
LocalQuickFix(to get a highlighting range on hover) - Understanding how to customize the floating icon.
- Moreover, my IntentionAction is placed after a LocalQuickFix even though I’ve set:
override fun getPriority(): PriorityAction.Priority = PriorityAction.Priority.TOP