the vid is NOT GOOD.
the washer is installed in the correct posittion see the white nylon square.
if the washer was added to the washer side of the backplate it would suspend the backplate off the CPU-mobo metal plate no??...and that would stress the MOBO area not the reinforced metal plate area...
with the stock setup the t-nut was protruding through the MOBO and the stud bottomed out on the nut and causes the ratlle. now the t-nut is below the surface of the MOBO and everything is snugged up.
JP