Thanks for the input guys (and the quick response Alan!)
I think I will 1) cut a 3"-4" hole in the shelf, 2) move them out from the corner as far as the shelves will permit (another inch or two) and 3) toe them into the room just a bit. That combination should let the bottom woofer fire more effectively and give the inside tweeter a little more flexibility.
These things produce sound that is geometrically better than what I had, so a little downside in placement is not going to be very detrimental.
