Hmm, do you know whats the difference between calling "prepare" from autobuild or make a build with it and after make a second again?
Cause by doing "only" the prepare the build time looks much shorter for me 
just want to know if you have a specific reason why doing it this way, or just cause of it works like i often do 
I also have to take a look at your patches cause my tx power is ok by the driver default but the available are crazy values..
and thanks, many of your stuff is/was the base for mine 