You have to understand that the advanced performance racing was used on (Guitars) we should been completely revoiced. The 700s were revamped but not revoiced. APB also went into the 2014 limited sassafras 714ce, and is now in the 914's. But that requires an entire new build or revamping. That bracing is so specific that you can't just stick it in anywhere. It works in conjunction in specific ways. Did you notice that the 814 has the bracing going wall-to-wall while the 614 has it stopping half an inch before the sides? This is a classic example of the distinctions. Rosewood needs the bracing to go all the way across and touch the sides and join with it. Maple does not and so it was possible to float the back. Trust that if it was possible for them to make a better guitar by just looking advance performance bracing in everything, Taylor would do so. This is where the art comes in. Guitars are not formula alone. If they were a computer could make Ataris better than we ever imagined, but it's just not so.
Hope this helps!