'Double' 2.5mm² and 1.0/1.5mm² clips used to be very common, and widely used, but I haven't noticed any for sale for ages. Is that because they held the two cables close together, such that cable grouping factors would come into play, or is there some other reason?Double clips that ARE designed for two cables only seem to allow for the cable to be flat on the wall, not 'edge on'.
Kind Regards, John