Update:

I got my center channel and sure enough it completely blocks my TV's IR sensor.

However, the problem has been solved for all of $35. With the help of David Kandasamy @ My.TV, I ended up purchasing a MyExtender RF extender. I'm not really using it the way it was designed to be used, but nonetheless it is working and I'm a happy camper. I just put both the receiver and transmitter in my equipment rack and ran the wired emitter to my TV's IR sensor. Works great and isn't an eye-sore either.

Also, I contacted Onkyo about using the IR connection on the back of my 502 with a wired emitter and they said it would work, but it doesn't.