I think it's confusing to have two different lock functions. I was misled and I sure others will be also.
An improvement would be if there was a global lock status indicator in the top window field. It should always be visible and not hidden behind a menu item. And if the global lock is set on aprons or runways, the individual properties should also reflect the global lock status.
But I also thinks there are something wrong with the current logic for the lock function.
I tried to delete an apron, but that wasn't possible. The apron could not be moved either. In the apron properties, the lock wasn't set and in the menu apron lock was not ticked. I'm not 100 percent sure how I managed to unlock the apron, but I think I did following: Selected the apron edit mode and then cancelled the edit. In the the properties, the apron lock was now set and could be ticked off.
So it's possible to get a mismatch between the actual lock status and the indicators of the lock.