[Serusers] Running multiple instances of rtpproxy? How to set up in SER?

I have reached the point where a single instance of rtpproxy is about maxed-out, showing that its single process is comsuming 85% or so and climbing of the CPU available. That works out to about 600 standing calls, the bulk of which are G.711. This is a multi-processor/core system and I have several other CPUs not really doing anything, so I would like to start up multiple instances of rtpproxy, which rtpproxy says it can do, controlling them via AF_INET sockets instead of the default AF_UNIX. How you set up rtpproxy for multiple instances seems reasonably straightforward, but what you do on the SER side to let it know that these additional copies of rtpproxy exist and how you or SER divides call load between them is less clear. Is there any documentation or examples showing this done, or better still, someone with a working ser.ctl file who would be willing to show at least that part of their configuration? Ideally, I'm looking for a case where calls are divided among rtpproxies regardless of where they came from or where they are going, as I have one particular call source/destination pair that is absurdly large compared to all others, and that so it in particular has to be distributed across across multiple rtpproxies. Thanks in advance!