Hi bud,
Thank you for the feedback and the praise, really appreciate it! :)
This feature actually already exists. I am not on my PC right now and can't remember exactly what the setting is called, but you'll find it somewhere in the 'General' tab. Should be something like 'Display failed to find text' I believe. You can also turn off the border itself and only have the window visible when you hover it (border hover unfortunately only just got fixed in the latest alpha version).
Thanks again for the feedback. Let me know if there is anything else you'd like to see improved or added! :)