Don’t forget you already have a built in method for detecting the beginning of a hover on almost every UMG widget: the tooltip. You can bind a function to the tooltip instead of just entering text, and that function can call a custom event in your widget graph, which can call any other custom event if you route it through the right ownership. The tooltip only initiates on hover, but it’s easy to use a delay to check for un-hovered. Plus, you don’t have to do a check every tick.
Here’s an example of how I used this to make my own tooltip widget show (since the built-in tooltip text is horribly tiny on high DPI screens):
