Had a gander at the website. The products look well made but the pricing is going to limit your customer base on the whole to guys that can probably afford bigger boats. Taking that into consideration, the biggest issue I can see (unless mistaken) is that none of those designs can be used with an anchor in place. It is nearly almost standard now on a 6m plus rig to have an anchor winch fitted that permanently houses the anchor on the bow in the bow roller. If your old man can wrap his design skills around that issue along with making his designs suitable for the more common top end anchors like the Manson Supreme, Sarca and similar he may well end up a busy boy.