you can if you cut the diffuser properly, but it won't be even cuz the tips don't line up with the muffler...
see pics of my 14 550i with m5 comp package exhaust and standard 550i msport diffuser
you can see on the left where they cut the diffuser...
doesn't look bad, as he did a decent job and kept it symmetrical on both sides, but up close you can see it doesn't line up..
imho best to do m5 (or aftermarket diffuser made for m5)
