As usual, really awesome stuff Andrew!
Is there no way to set it to a lower resolution (and jpg?) in order to get more frames into that buffer?
I know some cameras add a limit even though the buffer is big enough (like the NEX-5n, where the settings don't seem to have any effect on the buffer. The NEX-6 is a little better though, I think I managed to get it to 18 frames at 10fps small jpeg before it slowed down to about 3fps.)