Instant improvement over Ender 3 Pro's magnetic bed! No matter what I tried, I couldn't get my new CE3-Pro's bed level. I couldn't figure out if the x-axis beam was bowed up or if there was factory bed was bowed down, but with all four corners level to .10, the nozzle was .25 in the center of the print area. So... I ordered the CCTREE heated glass bed to see if it would help.
Turns out that I was dealing with both problems - a warped bed and a slightly bowed x-beam! Working under the assumption that the new bed is perfectly flat and bridges any low spots in the factory bed, I'm now able to level .10 on the corners with ~.15 in the center... which is just enough to get consistent adhesion in the center without dragging the nozzle out toward the edges.
Now I can print the parts I need to add a BL Touch auto bed leveling sensor, which should easily be able to compensate for the x-axis issue :)@