Maybe its changed. A few years ago it was a problem to DH in to PVG and entering the country on a crew visa and then DH out. The reason being is if they were granting you admission into the country using a crew visa, on the basis that you're going to operate as a crew member, then they expected you to be a crew member at some point. Otherwise, you're essentially using a crew visa as a tourist visa or something else, since you certainly didn't preform any crew duties.

This was a problem because there were a couple companies that were having crews DH into PVG where they sat for a few days (reserve or waiting on a plane) just to have them DH back out without ever using them. This is what got the Chinese excited.

I don't know of anyone that got anything more than spoken to over it.

It sounds like the OP is just trying to transit the airport which is completely different than the DH on a crew visa issue. I don't think there will be any issues.