Hi, I have never done this and I have actually been searching the internet for a logical explanation how to create custom UMG components that would show up in the Widget Editor Palette that you could then drag and throw in your widget.
Any widget that you create will automatically be added to the palette that can be added and used an any other widget. They will be under the category of something like “user widgets”
If you want to create a Slate widget you have to make an SWidget with a UWidget counterpart in C++. Or you can just make a UUserWidget in C++ if you don’t need to actually build the layout of the widget in C++.
What about the render side of the widget?
Im not sure what you mean? You can change the visibility of user widgets you add to another widget and control when they render with logic.