It took me some time to figure out why I got no rollout visible on script execution.
Before I checked it's predefined position which is [1500, 120]. (I'm on a pretty old laptop with [1366,768] max resolution)
I'd change that value to something like sysInfo.DesktopSize / 2.0
And something bad happens at line 56 when I try to run it with a fresh scene.
>> MAXScript MacroScript Error Exception:
-- Runtime error: array index must be positive number, got: 0 <<
selectedMtlClass = classof MtlClasses[nsBatEdSavedShader]
Hope it'll help you make it better