Gary,
We had route generate procs in several high volume interfaces and there was considerable drag on processing throughput. They are high maintenance as you must build the equivalent of DATAXLATE keys perfectly and then put braces around those suckers. A pain in the backside! We have retired them all now.
I would suggest looking at doing a Tcl Trxid procedure where you can interpret data and set routes. These are easier to build and maintain and provide optimum routing flexibility.
If you need some route generate code we still have our old suckers.
Let me know and I can email or post the logic.
Enjoy.