What difference does it make having an on/off button? Surely it’ll work exactly the same as holding the ‘enter’ button?
I've always found the lack of an on/off switch a bit annoying.
In my last van, I wired in a switch before the controller to turn it on and off.
The issue is you have to press and hold for a second, there's a bit of lag before it turns off. If you have a big glove on or maybe big fingers it's easy to press it and accidentally change the function rather than turning it off.
This happens to me everyday, I go to switch it off and it turns to bat or cal and then I start changing settings by accident, its a minor frustration but I always thought it was a daft design why not just have an on/off button.