If you approach the car and you do not get in, the door will close when you walk away. If you stay close enough to the car after it auto closes, it will not auto present until you move further away. Optionally, you can manually close the door and it will not auto present again until you leave the perimeter. I have only had this fail a few times, but not enough to warrant me turning it off.
If you approach from the front, it will only open partially until you walk by the door. Then it will open all the way. This occurs every time for me and has been demonstrated in youtube videos. So, I am not sure why that is not working for you.
My wife has her key in her purse. Every day when she takes her car to work and returns, my X door auto presents. And every time but twice, it didn't reclose. Success to failure ratio for me has been at lease 200 to 1. And the one time it didn't work, I noticed I had a firmware failure and had to hard reset the car.
When I know I am going to work in the garage or only hand wash my car, I do not take the key with me. I use my cell for all car activities.
I just wanted to share my auto-present experiences with it being turned on for almost a year.