One of the issues in this is that the ships of McKay, Webb, and Pook were largely "American."
They fit into a short historical niche as Cape Horn ships racing from the East Coast to the West Coast. Their acendency was as brief, chronologically, as the era of the "tea clipper."
Most of either ship wound up in the nitrate trade. Which was complicated, as the focus there was on volume of delivered material, and not the speed of the delivery. Which also was an issue in the Australian baled wool trade, too.
But, that "American" focus can have less appeal to European moders, which will be one of the first things a company like RoG is going to consider.
Also, the ships are going to complicated kits, with lots of repetitive parts as the various innovations of sail were applied the the Cape Horn ships to allow them speed with fewer hands sailing aboard. It's one thing to have a Stephens Brace winch aboard, modeling one is complicated, and rigging it doubly so.
And, the ships of McKay and Webb were bery "busy" with sails. Topsails and topgalaants were typically doubled, and royals and skysails were common. With long pole upper masts to fly moon sails common ehough, too.
So the main mast might carry:
Course
Lower topsail
Upper Topsail
Lower topgalant
Upper topgalant
Royalsail
Skysail
All that before stu'nsails and spars for those.
All of which increases parts counts (and complexity for moulds to cast the parts).
Also, thous spars are not hice, thick, chunky 17th century dimensions, they are a mis of iron and steel and very fine 19th centurey woodwork--not ideal for styrene at 1/96 or 1/100. Chain falls for for sail clews and topping lifts, wire rope penants for braces, all further complicate the building. As do the sizes of then-modern irno-stropped blocks, which will be half the size of wooden ones.
Despite trumpy and dragon to the contrary, most kit manufactures want thei kits to be 50% "finisha-able" as that spurs sales. Having to include wire, chain, brittania is going to be daunting (and not cheap to the kit manufacturer). Opening the box to then close it in the face of a few thousand parts, and stash it in the closet of shed does not sell kits.
Now, for 2¢ what would actually make more sense for the kit manufacturers would be to whip out some of the coastal traders. Simple coilliers, schooners and the like. Smaller ships, simpler rigging, easier to build for the novice; a delight for the experienced ship modeler.