It would have to work. The engineers cannot remove opening with the key in the Fob. I have had to use it a number of times due to weak batter of such in both my Sorento's to get in and start with the fob against the button. Issues resolved replacing the battery. If you cannot get in you can be stranded somewhere.
I did a true test on my 2015 with the battery removed from the fob. Gain entry and start with the FOB on the button method. Work, so I know even if the battery is weak its going to work. Note, our vehicle have the immobilizer in Canada, hence not a patch. But I needed to know as my wife phoned me since she couldn't get in or start and I had to drive down with the other fob. Fortunate it wasn't far away.