[Closed] Disable MaterialEditor thumbnails?

Not necessarily with MAXScript, but yes, you can go to the MEdit Options and enable “Manual Update” and/or “Update Active Only”.
In the first case, you will have to click the sample to update after any number of changes.
In the second case, only the selected sample will update, the rest will not unless selected.
You can also set the MEdit Renderer to VUE to completely disable any rendering, since VUE does not generate any image.