Hi Max,
Oh by "proprietary" I am referring to any system not based on ANT+ Device Profiles which use the ANT+ Network Key. Sorry for some reason I thought your system was not based on the profile.
Correct, it has been discussed but at this time the ANT+ FE-C Profile does not define a standard group training control method other than CSM at this time, but there are certainly other methods using ANT which would be more radio efficient (master shared channel topology) or with more large area control (scan and forward master/background scan mesh).
Only ANT+ Alliance Members may submit requests for profile extensions. It would also be possible to implement one of these other methods concurrently with the FE-C broadcast channel.
Cheers,
Harrison