Is it possible to have a "power" sensor in HomeKit?

I have a virtual indigo device that simply is "on" when the real device is on and "off" when it is off. I can show this in HomeKit as a switch and it accurately shows On/Off to show the correct state. However, because it is a switch, the user can manipulate it and mistakenly think something should happen. It's also possible for homekit to get out of sync with Indigo if this happens.

I tried adding the device as a contact sensor and this works but now the HomeKit UI shows the state as open/closed rather than on/off. The user can't manipulate it which is good but the semantics are a bit confusing to the uninitiated.

Is there a way to add a device to HomeKit such that it shows as a sensor but displaying on/off values? I don't see anything in the HomeKit-bridge ui but maybe I'm missing it.