Run a full bed mesh to map how flat the surface is above and below the level of plane. Rather than using this for compensation, we'll use a full bed mesh in this step to visualize warpage on the plate and evaluate not the bed level, but how warped the bed surface might be. This warpage can become overly pronounced and undesirable if the bed screw tension is to high, for example, and by inspection we can make adjustments that can improve the warpage, resulting in a bed that's more flat and requires less compensation (and corresponding z axis movement, which also means time) when printing.

We're basically checking to make sure that there's not much more than a variance between the highest and lowest points on the plate of about 1.5x layer height thickness. In practicality you should be able to adjust bed screw tensions when leveling so that the variance is under 0.250mm.

If the bed is too warped I recommend unscrewing the bed screws all the way and they returning them back 1 1/3 full revolutions and re-leveling with SCREWS_TILT_CALCULATE. We don't want to much tension on the bed screws as that pushed more on the plate, while we also need enough tension so its not sloppy and becomes to loose.

After any adjustment of the bed screw tension be sure to relevel the bed, preferably with SCREWS_TILT_CALCULATE.