However, I fully expect it to be exactly as you say and MZ will run the first play each series he is in and get stuffed for a 5 yard loss followed by desperation passes. The conclusion will be he wasn't ready when in reality LSU simply assumes Kelly will call read option the first play every series with him and thus will stuff it.
If he just ran a normal offense, and we had practiced all year running much more so we could execute well by the 13th game of the season, it wouldn't be all that bad to use both QBs. MZ just brings one extra dimension that randomly gets used to keep LSU off balance.
Alternatively, if he uses MZ in short yardage situations no matter where it is on the field, that could be good because LSU has to assume he will run the ball -- and may also pitch it when the read dictates to do so -- so it is harder to defend. That again assumes Kelly randomly uses read option versus does it the first play of every series.