Agreed! I recently had to press a ZEN17 Universal Relay (which switches landscape lighting in the summer) into service because it can have its inputs set up independently of the relays–the same kind of thing you would get with a sensor having terminals. It’s now monitoring my sump pump to see if the motor runs while we’re away for the winter, using an AC current sensing device with dry contact relay output. It works, but I’ll still need a replacement when it goes back to landscape lighting in the spring.
One could hack a simple contact sensor, say a Zooz ZSE41 800LR Open/Close Sensor to get the job done, I suppose…
You might be interested in the FIBARO Smart Implant Z-Wave Plus, FGBS-222, which has a slew of various inputs–although it’s a bit more expensive and perhaps overkill for your application.
Next spring I’m going to look at it for some monitoring functions at our home, including temperature/humidity, perhaps motion (using a hardwired PIR device) and maybe my garage doors. That would fold four devices in my garage into one…
(It should work okay with Z-Box: can you confirm that, @Sara ?)