Late to the dance I know, but, IMO a 5'11" woman does not need the services of a framebuilder specializing in WSD. Terry pioneered the use of 650B tires to get women the same kind of toe clip clearance and other ride characteristics that men enjoy from conventional designs. Why? Because the average woman is 5'4". Many are under 5'. That's Terrys market. The hard to fit shorter woman cyclist. The modern penchant for sloping top tubes has led to a number of 400mm and 450mm seat-post designs so seat-tube is irrelevant anyway. When you are taller than 5'. The o.p. simply needs to find a top tube or effective top tube that works with her dimensions. This can be done, and easily too, as the o.p. must fall into what is generally a common dimension for men in the 5'8" range. I am a very average proportioned 5'10" male and my bike fit follows all the accepted tests. This does not mean I am comfortable on it all the time. That's why recumbents exist. When you have measured accurately all your relevant dimensions and input the data on a site like the Competitive Cyclist website, they give you three different fits to experiment with. One of them will likely work. I have seven different bikes ranging from 24" down to 18" but all of them have an effective top tube around 22.5". On one I have to use a 90mm stem and on another a 110" and one has a zero offset stem. And everything in-between, all to arrive at a seating position that is very similar among bikes. Being oddly proportioned doesn't make one hard to fit with the amazing choice of stems and bars and the super long seat-posts that are being made in 6061 and other strong alloys. FWIW.

H