The necks are fine for scratchbuilds, or even for say a TL-1H where you can easily move the bridge back a bit. About 0.5" for the 27" neck and 1.5" for the 30" neck. But you can't do that easily with a standard Tele bridge because of the pickup rout, or a Strat trem bridge because of the trem rout. Much filling and re-routing required.

On the right guitar, they're fine. The JZ-6 baritone has the same length 30" neck, but the body is purpose-designed to match it, so there are no intonation issues with it.

Adam will do some double checking, then contact the factory and see what can be done. Hopefully he'll be able to get some correct length conversion necks in stock.