Real world experiment..
OK so I found I actually have a XLR out to 1/4 in cable converter with a high/low ohm switch. So I took my MB115 to the guys house and tested running from the XLR direct out into the Active input. It worked fine with the cable switch set to low (I believe it was on the low ohm). I ran test both ways just so see if there was any differences, which there was:
1. MB212 direct out IS a direct out. Only the initial gain control affects it
2. My MB115, the direct out is actually patched in between the Boost and Master gain controls! Changing the EQ, and/or Boost also affected the signal going into the MB212.
3. The MB212 is hissy as **** compared to my MB115. I was really surprised at the difference. However, the hiss was not present on the direct out, leading me to believe the hiss was induced in the power stage of the MB212.
So the answer to my original question is: Yes this can be done with just a cable! Because of the notable hiss, I didn't buy the MB212, but maybe I should.....I just couldn't put the trigger....damn that quite MB115!