Karl,
One last question if I may? As long as the edge of the board is routed and advertised as suitable for hidden clips, could I use the Ipe clips extreme for kiln dried boards? I think the spacing is 7mm? It’s just that 2 of the places that I am thinking of buying from advertise their own favourites, one of them being the Artichoke clip, but these look a bit like flimsy plastic.