That will give you an audible indication when the cutter connects with the plate but has no feedback to the control board to stop the z-axis movement (or any other axis that you would probe on). Therefore you would have to do a very slow axis movement with very little steps. I doubt that this is faster or easier in the end than just doing the same with a piece of paper.
If you want a cheap and easy solution, take the same parts minus the Multimeter and connect the leads to the SO controller board like described in step 3 here. That will allow you to probe with a simple G-Code that takes care of everything.