In Polygonize volume, deviations occur in the background and material grayscale values.

[[Fe...]]

After automatically extracting volumetric elements, polygonizing the extracted area may cause errors in background grayscale values or material positioning. Following material recognition processing, two distinct grayscale values may appear for different materials. See video for details.
Question 1: How can I determine whether the grayscale value for Material 1 or Material 2 is correct? What is the difference between the two?
Question 2: How can I quickly identify the correct background grayscale value and the correct material grayscale value (Material 1 or Material 2) using a script?