Until the ISY-26 has a way to load the Insteon linkages into Elk, I would suggest using PowerHome for link management and loading into the M1.If you're going to go Insteon, consider the purchase of an ISY-26 for your link management, scene creation, etc. - and possibly events & triggers. SO EASY to program, and it's really a great device, and they seem to be working closely with Elk on integration.
The ISY-26 is supposed to support the M1 with the next firmware release but I can't find any details on what that actually means. Will it be able to load links into the ELK? Will it be able to trigger actions from individual Elk zones? Or will it just be able to arm/ disarm the M1 and keep the Insteon device status tables in sync between the two systems?