I have been playing with using tkinter to make overlays so some information would appear on top of the rest of the screen.
I'd rather not have this window block the mouse. Is there any way I can have it so click events pass though my overlay? So the window below my tkinter app receives the event.
No, there is nothing built in to tkinter that would allow you to do that. The best that you could hope for is to capture an event, then use some sort of platform-specific tool that lets you create new events, and use the coordinates from the captured event to generate a new, non-tkinter event.
How to make click events pass though a tkinter window?