Is this the best CNC router bed?

[Cazual Haze]

Hi I have been upgrading my old CNC router and have come up with I think the best almost crash proof bed money cant buy.
The premise is if the cutter touches any of the metal on the bed it forces the machine into an E stop! Saving your expensive cutter and work.
Thats the theory take a look at the video and let me know what you think.
Cheers