I also have never activated an account on the car or app. Updates are pushed anyway.

I had a black infotainment screen once at some point. That's absolutely unacceptable. I managed to clear it manually after some frustration.

I updated to 4.1.4 (or was it .5?) a few weeks ago. Afterward, I had a problem with maps on the driver's console being JLR's, while Apple's map was on the infotainment screen. That was very annoying. It fixed itself the next time I told Carplay to navigate somewhere (I think that's what fixed it), and it's been fine since then. No other issues so far.

I am unsure what to do about future updates. They may include genuine and needed fixes and improvements, but they may also screw things up. For now, I'm ignoring the latest pending update, as 4.2's change doesn't add anything important to me.