Thanks for the insight .. I will now write code to determine if this feature is available on the HTC Rhyme and what to do about it.
As for contacting the phone manufacturers, it is not very easy to do.. In the case of Sony-Ericsson, they don't have any obvious means to make contact at a developer level. Also, they really don't appear to be set up to be interested in this kind of feedback - feature phones don't get much support, and so on.
As for HTC, I've tried but also can't find any way to communicate in an effective way. It seems to me that this feedback loop ought to be a function of the ANT Consortium itself - isn't it possible that the ANT group themselves have the internal contacts to implementors that can provide this feedback, somehow?
It seems crippling to me to be having to resort to workarounds to get this feature implemented, when the spec for the technology itself states that the method for scanning be implemented. A little more thought ought to be put into this relationship between the ANT group and hardware implementors - in the past, it has been well proven that such failure to communicate on viable, valuable features poorly or not-well implemented has led to a market death. I can't imagine anyone using ANT effectively if they have to keep entering ID's and whatnot to find their devices - what will it be like when ANT is ubiquitous in the bathroom/residence, multiple ANT devices around, and we have to uniquely pair/resort to dire hacks to get scanning working? For the end-user, its far more usable to just have scanning work properly - if hardware implementors are crippling this feature, then ANT itself is being crippled in the marketplace. This is why I believe the ANT consortium must care about this issue a bit better and I hope this message is not lost in the noise ..
I will now go ahead and implement a workaround hack for this, much as it makes life miserable for the user.