Isaac,
I would encourage you to spend some time looking through the screens on the QU-32-maybe best if you learn how to save your settings as a scene though.
I have been using a QU-32 for a couple of years now-and I have to admit I have never assigned or chose pre/post fade using Kemper's method-though I have frequently changed these settings for too many reasons to go into.
If you select a channel, the choose the "Routing" button next to the touch screen, then select the "Mix Send" tab, you will see (and be able to change) all of the mix sends for that channel. Other tabs here give even more fun options.
I learn best by wanting to do something and figuring it out-but 30 minutes reading/skimming the manual will give you a idea of where to look. Then there is always reading other posts and learning something new like I did as well!