Shim to level print bed

I saw a video on youtube where a milling machine levelled it's own bed by cutting a tiny layer off the surface and thought this concept may be a good way to level your bed for cold bed printing. It's opposite of the milling concept but it should work.

The idea being that as you print the shim the height differences would be levelled out by the act of the plastic not being squashed down on the low parts. As more layers are printed the process finds the level by gravity for the low areas and c