Why does the info property of a NetStream publishing P2P on RTMFP show 0 for videoBytesPerSecond?

I'm working on finding a means to detect bandwidth/latency issues in some Flex video chat software, other than what we're already using, and one thing I was looking at yesterday was NetStream.info.  Of course that's of the type NetStreamInfo, which has the property videoBytesPerSecond.

For RTMP connections, I saw that the value always appeared to be fairly reliable, whether the NetStream was publishing or receiving. Generally between the bandwidth the camera was allowed to use and the bandwidth that our client machines had, I would see values more-or-less around the lesser value always showing up in that property.  (This is without doing much more than using NetLimiter to try to trip it up, and it roughly held up under pressure in that scenario.)

For RTMFP connections, this is not so.  The receiving NetStream does fine; you see the correct number of bytes per second showing up in that property.  But for the sending NetStream, you just always see 0.  The same goes for a whole host of properties in the NetStreamInfo.  It's just like NetStream.info isn't tracking anything for publishing, P2P RTMFP streams.

Why?  Is there a work-around or something?  I would like to be able to use these to track latency issues and to know which side they're happening on.  If only receiving streams can be relied upon, that's make it harder to isolate issues to one side.