Work In Progress..
- '18 CX-9 Signature
My point is that there should be some way of turning the auto lift gate on or off.
I see, that point wasn't clear.
I'm not aware of any manufacturer that has that option on their keyfobs, so even if you never buy a Mazda again, you still wouldn't have a solution to your problem.
I suppose you could try removing the button from the keyfob to disable it? Certainly wouldn't be as easy as a simple lock switch though.