Richard - Thanks for sending your diagram, it helps to see things 'visually'
Cort - Thanks for the heads up. Now that you've mentioned it, its obvious that MMDVM clients could connect straight to hb_confbridge. Doh!
The code change adds about 5 lines, so not much is lost if it turns out to be unnecessary - although there may be a use case for my change.
We can pick this up when you get time - I'm in no huge rush.
Thanks again for your help,