Oh no, not power strips!!!
As an electrician I understand where UL is coming from they are coming from but also know what goes on in the real world, do a piss poor job distributing power at large event and you better get used to lots of strips and cords. And the FM to be on your rear end screaming about shutting your event down.
Start running proper event power setups and provide pits with MWBC tri outlet boxes if they are serious about this issue.