When numatb file contains many materials, selecting materials at the bottom can only be done by dragging the entire window up, then back down to edit the properties. Adding scroll functionality to the left tab will make navigating this easier.
For reference when making a mod with many alts I like to make a universal material that I later remove the unused entries from, that way I only need to 1 numatb for testing purposes before finalizing materials.
When numatb file contains many materials, selecting materials at the bottom can only be done by dragging the entire window up, then back down to edit the properties. Adding scroll functionality to the left tab will make navigating this easier.
For reference when making a mod with many alts I like to make a universal material that I later remove the unused entries from, that way I only need to 1 numatb for testing purposes before finalizing materials.