All forums have this raised by owners, as the stop start is part of emissions test it isn't possible for it to be permanently turned off. If you buy a GLE450 there is a 48 volt battery that starts the car and it is seemless, I have always turned it off after starting on other cars but don't on the GLE.
2017 GLC AMG43 premium plus, night pack, leather, intel lights, 360 camera, side steps. = sadly gone
Now GLE450 Premium plus, Selenite, Black/White Nappa leather, Tech plus pack, Driving assistance pack, Tow pack, Off road pack, 22 inch wheels.