Laying out a 12 fret 000 with falcate bracing

[Jim watts]

As the topic suggest I'm trying to mash together Trevors book plan with a Martin 12 fret 000.
I notice that when lining up the 12 fret body joint Trevors soundhole is shifted approximately 32mm forward (towards the body joint) this would allow for 18 frets without extending the fingerboard into the soundhole. Seams reasonable and correct to people or would you lower the soundhole? I'm inclined to keep Trevors position giving more soundboard between the bridge and the soundhole.
Has anyone done this and if so what are the gotchas I need to be planning for that may surprise me?
Thanks

[joel]

I'm currently building a 12 fret OO.

I overlaid the falcate bracing plan from the Build book on the body plan to get what looked like the best saddle position. Together with a 630mm scale length resulted in 12 frets to the body. I also get 18 frets total. The result is quite a pleasing look to me. The result is a little like the right hand guitar in the pic attached. It's from Taylor, showing the difference between their OO bodied 14 and 12 fret guitars. However, my sound hole didn't move down quite so much.