In my experience, it is rarely necessary to inherit from the UI leaf classes to accomplish something in Urho3D.
I’m not sure how ‘doing a mini-roguelike framework’ would preclude using a scene manager and require inheriting from Text and Window. This seems like an ideal candidate for a scene manager, with the Urho2D system sitting on top if it’s a 2D roguelike.
As for your world map window, this is a good candidate for a scene that is rendered to texture then displayed as a sprite in a UI element. For example, in this prototype world-map screen shot from my own game:
The world map is its own separate scene that renders to a texture. The texture is then drawn as a Sprite inside a Window. No need to inherit from anything to implement it, it works with Urho3D right out of the box. This can of course be done with any scene: a 3D one as in my example, or a 2D one with sprites for a 2D world map, as in this prototype of mine:
(This had the cool benefit of being able to reuse the rendered texture for the in-world map table graphic.)
Typically, the only Objects I ever need to inherit from are: directly from Object (for subsystem-like systems) and from Component (or, more commonly, LogicComponent). For everything else, basic Urho3D objects are usually sufficient.