Last time I was at PVG it took me 20 minutes for immigration on a DL flight and 20 minutes for 3 bags. For an MU flight I would say their would be less foreign passengers, so maybe the immigration line would be less.

Also, I don't remember of being able to transfer before immigration. I saw the sign, but never seen anyone actually go that way my 4 times being in PVG, unless it's an international transfer maybe.