I haven't tried any of this, so I am just guessing. But yes, choose the "<DEVICE> SC" then either "A scene is activated" or "A scene is de-activated", name it, and enter 1-8 corresponding to a KPL button number. (Remember an 8 button is 1-8, and a 6 button is 1,3, 4, 5, 6)
However, I would question why you would want to call an Insteon scene from Vera when initiated by a KPL. But here goes some ways to do it?..
It depends on your setup.
Case A) If you have the KPL button setup as a Controller for an Insteon scene or kicking off an ISY program, Vera need not be involved for Insteon devices. If you want to use that KPL button to alter Z-Wave devices within Vera, you would use the KPL activation as a trigger, and set the Z-Wave devices as you want. Ignore any Insteon.
Case B) If you do not have the KPL button setup as a Controller for an Insteon scene or ISY program initiator, Vera could handle it all. You can have the scene set the Z-Wave devices as you want. Then you can also have Vera set the Insteon devices as you want, or you could have Vera call an Insteon scene that you already defined in the ISY.
Clear as mud right? It's flexible to the point of being too flexible! The reason I would use Case A over B is less network traffic and ease of use. Insteon/ISY will nicely handle the Insteon side of things. And let Vera handle the Z-Wave side. This cuts down on Insteon traffic, IP traffic, etc.