those magnets have a very narrow field and they aren't anywhere near the monitor or HHD so there is no problem
also because the field is so narrow the width of a finger isn't close enough for the magnets to engage fully, so if a finger got in there you could get it out, without serious damage(this was a real concern for me)
In my design the metal plate is in the front of the cp and the magnet is inside the cab latched to the front of one other the cp's that is not in use, so no springs or anything fancy, accept that I need a way to turn that knob from the outside that may take a little bit of engineering