Thing is, the average Les Paul fan already has a million and one choices. It's one of the most-copied designs around, and from hollow versions with P-90s to thinner, larger-fretted versions with active humbuckers, you can already buy pretty much every variation of core parts you can think of.
There are also a couple of other parts/kit manufacturers which make LP copies far closer to the original design, but still with many options, and several include set neck construction as an option.
We're also at a point where carved tops have well and truly stopped being exclusive to more expensive guitars. There was once a time when a carved top, single cut guitar was something you worked towards, and you started with a flat top, single pickup version. Then along came the Studio and Faded models. Then Epiphone went into full swing, and shortly after that, all the other Korean and Chinese copies. Now you can buy a carved top Gibson—Gibson, not Epiphone—for under £500.
I wouldn't be at all surprised if we heard the Royale and Regal bodies are some of Warmoth's worst-selling ever. Between the competition for the style and the price, there's really very little reason to buy one. There is the drw of less common wood choices and finishes, but your average singlecut fan is going to always go back to mahogany, and a full Warmoth build costs the same as or more than an off-the-shelf Studio or Tribute Gibson LP and a professional refinish.
Come up with a single cut design that can benefit from the cost-saving methods the carved Tele uses, or find another way to lower costs, and then I would expect a Warmoth single cut to sell well. As it is, I would be more surprised to hear the Royale & Regal have sold well than I would if I were told they've sold poorly.
