I imagine having 50% of your signal in front of either channel is going to sound quite different to 100% in either channel. A better experiment might be to have your guitar split 100% into the fromt of both channels, and then run your stereo panning pedal in the 2 separate fx send and returns.

I've built a couple hollowbody guitars (similar to the PRS hollowbody) with a stereo output that I send to both channels simultaneouly.  With a switch on the guitar I can send the piezo to one channel or the humbuckers to the other channel.  I can also select both channels and blend the piezo and humbuckers and the two channels.  This is a great setup for this amp.  I feel like I'm playing two guitars into two amps with options to play them all at once.  I can easily switch from a clean acoustic sound to a overdriven lead tone or blend the two.  The effects loops add many more options.  This is a great amp for these types of uses.