When in doubt, RTFM!
I don't know about the Cor-Bon rounds specifically, but all I could find in the M&P owner's manual is this:
From Page 11
"Plus-P” (+P) ammunition generates pressures in excess of the pressures associated with standard ammunition. Such pressures may affect the wear characteristics or exceed the margin of safety built into some revolvers and could therefore be DANGEROUS. This ammunition should not be used in Smith & Wesson medium (K frame) revolvers manufactured prior to 1958."
"Plus-P-Plus (+P+) ammunition must not be used in Smith & Wesson firearms.
I don't own this model, but I downloaded the manual for it and this seems to be a pretty generic statement found in most of their manuals (from what I can tell)
In other words, enjoy your +P rounds in your 9c!