The MBA1s I knew trying to do this all blew off the exam in the fall. I think they might try next set of exams. I would really think it might be more possible in the second year, when the pressure is off a little more. From what I have read of people trying to combine, they would most likely get to having level II on completing and work on the final exam when in a job (the dirty canuck at Chicago found this the solution).
A lot of it is best intents and whatnot. I would also add that if you are not going into buy side or analyst roles, no-one seems to care about it. If I could see a good reason to do it I would, but I honestly feel like I am hunting reasons to do the exams.
As for my Treasurers exams, they are a UK designation anyway. I might just finish it off (I have a Corp Finance and Liquidity exam, which by the fall I should pass without even studying!).
I should add that I really think doing an MBA part time is a big enough eat of your life as it is. Anyone I know who has done them found they didn't have any time as it stood.