Hey Bo, this topic came up earlier and to my (unresearched at this stage) understanding of falsetto, it is a vibration of a thinner part of the vocal cords. I have a stupidy loud and high falsetto voice. I feel in the upper regsiter there is a couple of ways of approaching it. Re-shaping the lips to find a thinner bit of lip tissue to vibrate – NOT DESIREABLE, THIN SOUND – or regular setup with thicker lip tissue, possible slightly more work required as there is more lip tissue vibrating BUT the sound of the full voice in upper register.
I will keep this in mind as I begin filming the Emerald and Diamond Master Series videos.