Have you considered making a Z-Wave bridge + Access point? I’d like to integrate a few Z-Wave devices, but I’m dead set against using a home server application to do it due to the lack of reliability and poor security inherent in most of those applications.

A device that simply mapped Z-wave controllers to Insteon Responders and vice versa would do the job–similar to what you’ve done with the EZSns Dakota bridge. This would enable the use of the far more sophisticated Z-wave remotes such as the Harmony 890 and provide seamless and serverless bridging between the two most popular new home automation protocols.

A function to act as a phase coupler could be implemented by simply encapsulating Insteon packets into Z-Wave packets and forwarding them to a matching linked Z-Wave adapter. This would obviate the need for Insteon phase couplers.

Personally I think Insteon should just adopt Z-Wave as their RF protocol, but I doubt they’ll do it. This would allow end-users to make that choice.