You must assign each device two unique names when you enroll it. Insteon says HomeKit requires devices to have names that are different from the one that the Insteon hub uses. This is confusing because you see the Insteon name in the app, but must use the HomeKit name to have Siri control the device. I'm not certain if this is actually a HomeKit limitation or if Lutron just figured out some way of getting around it, because Lutron's Caseta Wireless Smart Bridge Pro doesn't require two names for the same device.
One feature that Insteon provides that Lutron doesn't, on the other hand, is an easy way to identify which device is which. Go into the app's Edit mode, bring up the device you're looking for, and click Identify. The device assigned to that name will chirp. Insteon is also to be commended for the huge variety of icons that can be assigned to each device--they have icons for everything from pendant lights to lava lamps to office chairs. I guess that somewhat makes up for the two-name confusion.
Rooms and zones
Once you've installed a number of Insteon devices, you can assign them to Rooms and Zones to make it easier to control groups of them all at once. A Room can be whatever you want it to be, since it's a concept and not a physical limitation, but most people will assign all the HomeKit devices in their home theater to a "home theater" room, all the devices in their master bedroom to a "master bedroom" room, and so on.
Once you've done that, you can control all the HomeKit devices in that room with a single button press or Siri command, and you can program all the devices in that room to perform the same functions at the same times. The same goes for Zones, except these are groups of Rooms. Assign all the rooms in your second story to an "Upstairs" zone, for instance, and you can turn everything on or off in one fell swoop. You can do the same for all of your exterior lights, which you'd need to control with in-wall switches, which Insteon can provide.
Scenes and schedules
Scenes enable you to set selected HomeKit lighting devices to predefined values with the press of a button or with a single Siri command. I created one labeled "Romantic Dinner" that turned the light bulb connected to the On/Off module off and dimmed the two lamps connected to dimmers to 40 percent. You can create as many scenes using as many devices as you want, but you must select each individual device that you want to include in the scene--you can't enroll an entire room or zone. Here again, Insteon provides an impressive collection of icons that you can associate with each scene.
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