This trick doesn't work with bpatchers because they're a window into another subpatcher - as such, they don't have inlets in their normal state. To add this object to Presentation mode, you'll need to either use the object's inspector to set the attribute or select the object and choose "Add to Presentation" from the Object menu.
Not sure if this is a bug or a feature, but toggling @presentation for any object resets that object's presentation rectangle to the object's patching rectangle. This means that toggling @presentation is not usable in creating dynamic interfaces. I'm trying to show/hide interactive elements on a custom interface.
This behavior is masked in the video above because the presentation rectangle is unchanged from the original object's patching rectangle. It would be very useful to have this fixed and have the object's intended presentation rectangle be retained each time it is added/removed from the presentation.
It should possible to see this behavior in the patch below. Notice that upon removing and re-adding the number box from the presentation that the number box's presentation rectangle is retained, but is not respected in actual the screen coordinates.
As Mike said, it makes little sense to me that the presentation rectangle gets reset if the user has defined it as distinct from the patching rectangle. It effectively makes toggling @presentation useless if one is defining customized UI's, as I believe was the intention of Presentation mode.