Where exactly is the problem with having three '!' s in a string constant ?
Is there a way to stop the bootloader from jumping into some 'debug' mode,
stopping all normal activities, cancelling the upload and blabber 'Huh ?' ?
AWOL:
Why would anyone in their right mind want to put more than one consecutive exclamation mark in a string?
I think this is a non-problem.
It's definitely not a non-problem when the compiler produces executable code which is equivalent to 3 exclamation marks. I had that when using the Mega2560 for a commerical project development. Fortunately there is a version of the bootloader which doesn't have this problem.