How do you find it? Do you use it to open/close the door?
I recently installed the Orion Grid Connect Smart Garage Door Controller With Sensor which I got from Bunnings. I’ve already got a bunch of Grid Connect stuff and happened to see this one so picked it up.
I was just looking at the Smart Guys version and it appears to be basically the same thing.
In my case I have a roller door and I agree that the sensor (which looks similar to the ATHOM one) is a bit of a pain to install to work reliably. I kept getting “door opened” warnings because it would move in it’s track enough that it was registering as closed. In the end, I stuck a couple of extra rare earth magnets to the moving part and that seems to have solved my problem.
For those wondering, these things basically have a magnetic switch that registers when the door is closed (otherwise it’s open). They then have a simple two pin output which you plug into your door opener to trigger the open/close function.
For my particular use case, my motor doesn’t have a local input for that dumb switch, in fact the only way to open/close my door is either reaching up to the motor itself where this is a button behind a plastic cover) or using a remote. Given it’s installed at roof level you can’t reach it so I have added a wall mounted remote in the garage which is used to open/close the door if you are in there.
To make this kit work I have soldered the output from the smart controller to the button in the remote. It’s a work around, but it does indeed work.
Mine integrates with Google Assistant so I could ask it to open the door (which then requires a PIN) or close the door (which doesn’t). Part of the reason I got mine is that my roller door is getting old and sometimes doesn’t shut properly and when the wife/kids don’t bother to watch it and confirm it’s shut it can get left open overnight or all day long… I’ve not had anything pinched yet, but it’s a concern. I now get a notification when it’s open for more than 10 minutes so can then yell at the air to close to door or, if I’m away from the house, use the app to check its status (and/or look at my security cameras) and tell it to close. My youngest will often press the button to close the garage on his way out, then come inside and ask Google if the door is shut! 
As for my DIY remote hookup, I use the same approach in my cars where I have a button installed on the dash. It’s just a matter of finding a place to mount a simple momentary on switch and jamming the remote in there. I haven’t ever bothered trying to power it from the car as the batteries need changing so infrequently, but it’s something that could be done with a buck converter easily enough. I’m almost surprised there isn’t an off the shelf 12V module for sale by some company that does this.
