If you have the frame cleaned well initially(first clean) i think you are supposed to just let the brush touch the glass only where possible otherwise you wont get to splash and dash which is what wfp is all about.
I'm surprised about the 3 months because your system/layout was so good. Who gave you the info to do all that?As regards the question you have to be pragmatic.There is a window cleaners version of the hippocratic oath - first do no harm etc, ours goes more; first do a good job, but then you get the obvious qualifications, such as, are they in?