If you haven't already, I'd definintely check this out: Learn: Intro to Kanban Boards with Adobe Workfront (with the caveat that the recording is almost a year old).
I would agree that I don't think there's a whole lot of difference between the three, (at least under the hood). I think it really comes down to how you intend to use it. My two cents:
- Basic Board: Use this for anything (generic) that you'd like to display in a board/card view. Example: A sprint retrospective
- Kanban Board: Use this for a more traditional Kanban board view, with either "swim lanes" (sort of) per person, or columns to represent statuses. These boards don't need to be connected to actual projects.
- Dynamic Board: Similar to the Kanban Board definition, with the addition of rules/filters to auto-populate the Kanban Board with either tasks or issues connected to projects.