it should automatically shut down after applying the updates

Okay, that part it does for me though. That’s extra annoying for you then.

apply everything that is possible, then restart and apply the remainder

Yeah on one hand I get the concept, on the other macOS and Linux manage without, and I don’t really remember older Windows doing this either, so I wonder if there is a real reason why it’s needed, or they just engineered themselves into a bad corner…