Magneto-resistive (self-powered) switches?

It’s not enough just to be zigbee. To be compatible with SmartThings, it needs to use the zigbee home automation profile (ZHA 1.2).

For example, the Phillips hue tap mentioned above is a zigbee device which is not directly compatible with SmartThings, because it uses the green energy profile.

My guess would be that any EnOcean device would use the same zigbee profile as the Philips Tap-- without batteries, it’s just not going to have enough power to run the more complex profiles.