How true is your waste board?

I have a stock setup (1000mm 1.0 upgraded to 2.0) and the stock waste board, and I have not surfaced it. Used my new Z-Probe to zero the Z axis at each corner of the build surface.

The height difference between the highest and lowest corner on my waste board is 0.699mm. I’m thinking that’s pretty decent for my purposes, but would love to know what other folks have.