Hi, I’m new to the forum and am considering a Kadjar. However I have plenty of experience with electronic handbrakes. I’m also a driving instructor and by no means trying to tell you how to drive, but I find that when somebody is struggling to get used to hill starts the best thing to do is to set the gas at an appropriate level whilst you have the clutch pinned to the carpet, then lift the clutch up. You’ll be able to feel for the bite easily and in my current car at least (Peugeot 308) I find the releases it a lot less grabby this way.
Alternatively, and I’m not sure if this works on the Kadjar but it does on my car - try holding the button up whilst you get the clutch biting with some gas set. Once the car starts gently tugging on the handbrake let go of the button and it should come off. At least it does on the Peugeot. Sorry it’s not advice specific to you car but worth a shot. Good luck!