@Lando
True, it is not great that it launches calc even when the workstation is locked. I feel like they should have baked in a check for whether the session is locked for those app keys, while still allowing the volume control, for example.
I remember finding the behaviour of media transport keys a bit peculiar some time ago when I noticed I could pause Spotify from the lockscreen, but not Play again, and I wondered what determines which of those signals pass through. Haven't checked recently