"If they modify the fixture do they not void the UL warranty/rating and should then be made to aquire an independent testing agency to test and approve and give a '"label" similar to the UL "label"?? "
Yes, the original listing for the fixture is void.
Answer to the second part depends.....is the booth being sold as listed equipment?? If it is then there has to be a file for the configuration and testing that was done. No testing....No listing.
GJ
