I know that MMV2 is great for a cut, but can another supp be added into the mix? I have MusclePharm's Shred Matrix and thinking about 1 packet in the morning, then the MMV2 in afternoon and preworkout.

You will be fine with most any fat burner, whether a stim based product or something stim free like DCP.
I would try to make sure your fat burner does not have any additional yohimbine, but if you tolerate yohimbine exceptionally well then go for it as MMv2 only has 1mg Y per serving and I know many people who use proucts that go as high as 9mg/day.