Yeah, I did. I tried shimming one corner to see if it'll help, but one washer was too much. It was worse before the shim. You can see the values increase around the center of the bed. Here's my current topography after the attempted shim in the back right corner.

Bed Height Topography:
--0.32057 --0.14357 +0.05043 +0.16118 +0.18893
--0.35782 --0.15632 +0.02168 +0.14243 +0.16393
--0.33832 --0.11982 +0.06268 +0.19568 +0.23068
--0.31157 --0.08457 +0.11868 +0.24968 +0.29593
--0.35957 --0.14382 +0.05868 +0.17768 +0.21768


planeNormal x: -0.00 y: 0.00 z: 1.00


Bed Level Correction Matrix:
1.00 0.00 0.00
0.00 1.00 -0.00
-0.00 0.00 1.00