Ted, here are my views. Consumer IR, which uses modulation, has range, but cannot handle large data flows; that is why irda is not modulated, to enable a relatively higher bandwidth.

You cannot, therefore, modulate and demodulate the raw irda at each end and expect good results (unless you design a complex data buffering system to be stuck in between).

If you must use irda, you will have to accept the raw irda distance limitations.