, the UL requirements,
This reminds me of a similar conflict my former co had. They developed a completely new idea for switches to be installed in hazardous environments like petroleum plants or grain elevators. Currently, electrical switches must be enclosed in explosion proof boxes, and the wires in hard conduit. Installation is time consuming and expensive. So our co made switches that used light and optical fiber instead of electricity and wires. Without electricity you don't need any of that explosion proof boxes or heavy conduit.
The big problem was trying to get approval from UL. They kept coming back to us telling us they need to be able to measure the electrical leakage, and all sorts of other electrical parameters. But without electricity, they couldn't figure out how to test it. They were just too stupid to approve it. We fought with them for almost a year.