You are welcome!
I use the buttons and banners from the asset as UI, if you use TilemapLayer node it will not be a control node and might be a little difficult to treat them as UI in your scenes. For example you would like the UI to always be on top regardless of where they are in the node hierarchy, also you would want the UI to be static if you move/pan the map around. this works well with UI nodes, if you use other nodes (TilemapLayer or anything else) it will not treat them as such, or maybe you have a mix of both. However this depends on what you want to do in your project.
So I use banners/ribbons as a Panel nodes, and I use button node(normal not textured button) for button asset, then I use the Theme Override just like I explained in my last reply
This approach is better for me and it depends what you want to do in your project.
gl in your project!