I like the idea.
I think this would be really cool with worship music. You could have a soft slow ballad at the beginning intro and verse and in the middle have it switch to a heavy rock based part that switches back to the soft slow ballad.
You can do this already using the part markers, so you don't have to wait to find out how it would sound
If PGMusic introduces RealSets, they will might not be offering slow ballads that suddenly switch to heavy rock based parts... but you can do it already right now. Click on a bar, go to
Bar Settings and change the style or the drums. Select another bar where you want it to switch back again and again load the style. Experiment away!