If I have said it once I have said it a thousand times............. sleeps should be avoided. If you must use sleep anywhere you probably need to rethink your code/strategy. I'm not saying using a sleep is always wrong but I am saying it is the wrong answer 99% of the time.
Why not use mcSignalWait? Wait on that input to go false. Check your rc and do whatever you want after. Continue running, throw an error, etc.
Sleep will pause every script in the chunk it is called from. In macros, that is everything in the macros directory and any dependencies (required modules for instance). In a screen it is all the screen scripts and any dependencies required by any of it.