I got disgusted with UL a few years ago when I saw a design flaw in an MCC starter.
The operating mechanism for the fused disconnect blocked access to the fuse holders. The only way to change the fuses was to turn the starter disconnect ON and change the fuses while hot. I mentioned this to the guy at UL and he told me that they only test for safety when properly installed and were not interested in anything having to do with "maintenance".
I now consider the UL Listing as little more than a starting point when I'm deciding what to specify on a job.
