Theatre tech here, screw terminal blocks are not rated for being in any sort of flexing situation nor are they very good at stranded cable. It would be a bet

Theatre tech here, screw terminal blocks are not rated for being in any sort of flexing situation nor are they very good at stranded cable. It would be a better idea to get a cable specifically designed to break out to 3 IEC connectors. Or at least put the screw terminals into a housing designed for it.