"Though they may not be screwed into the magnet, they are magnetic (touch them with a screwdriver) and therefore connected to the magnet even if not directly."
If that's the test, yes they are ever so slightly magnetic (the chrome plate itself is more magnetic, however, and so are the screws of the minibucker in the bridge position). Just doesn't translate in an audible volume difference. Now you can of course argue that neither the soap bar TBs nor the guitar size humbucker TBs offer individual string adjustment, but you can at least slant them as needed. This you can't do with the TB Plus mockbucker because that rests in a cavity underneath the chrome cover without any screw adjustment for its height.