AWOL:
Known feature.
Of course, it begs the question - why would you want to print more than one exclamation mark?
Or indeed, except for ellipsis, any more than one of any particular punctuation mark consecutively.
Well to be fair, this 'escape code sequence' could be also triggered by any constant binary data array table, 0x21,0x21,0x21 (or possibly even from complied instruction code?) contained in a sketch source file (which would make it near impossible to figure out most of the time), so it's not just a matter of poor ascii english usage. 