@tloch Good catch on the number/string issue! I agree it would be good for us to sanitize the arguments, or at least put an error in the console if they are the wrong type. Can you file an issue for that, or even a patch?
Strange that the overlay isn't working when delayed. Are you using addOverlay?
Yeah, i'm using addoverlay()... I can post code when i'm home. And i can pretty much only reliably reproduce it on my phone because it seems line it needs to still be loading the image while the script adds the overlay