No doubt geo is excellent stuff but im still sticking with the traditional way so water cant run in. Like overanalyze, id only do it the other way if client signed off.
I did however do some of the windows on that farm house starting with the heads and running the legs up to it. Only on the first floor under the wrap around porch and the second floor under the eaves where it was less than a foot below the soffit. Made for a much tighter miter(actually a cope) when looking up. Small dab of osi quad behind the joint. All the gable ends exposed to weather were done heads last and took more time fitting.