UMG: behavior -> "Tool Tip Widget"

I want a custom tooltip to use for several dozen text boxes without having to create a custom binding for every single one. There is a dropdown menu called “Tool Tip Widget” where you can select a widget BP from the project (although nothing shows up in the menu). If this is a way to use a “generic” tooltip class that accepts the existing tooltip text, how do I use it?

I noticed I can bind it to… the other instances of widgets that are already elsewhere in my menu. I’m not sure what this would even do, and when I tried it, nothing appeared when I hovered over it.

Is there a way to create a good-looking custom generic tooltip (or modify UE4’s ugly one)?

[EDIT] I’m replacing the text blocks with custom widgets so I only have to implement one binding. Annoying because now in the preview they all say “Text Block” rather than the actual text but hell, I guess it kinda works. An answer here would still be useful, if only for future reference.

I briefly described both methods in this post:

That second one is what I ended up doing. Kinda annoying to have to use custom widgets instead of Text widgets but it works.