That's a clever idea, @tiffle!
I had a quick search of the forum for other ideas.
- If you don't mind the KM Editor being open, you might be able to use this to view variables supplied when your write to a file macros run.
https://wiki.keyboardmaestro.com/manual/Windows#Value_Inspector_Window
- This looks promising, and you wouldn't need to use any polling to get the results, as your current macros could update the prompt. I've messaged @avialan to ask if he'd be willing to share the code he used for it.