The chalk lines are like having an extra set of hands instead of floating a ruler is space while you consider how to interpret a complex shape. A lot of what I build is design as you go and never gets formally drawn up until the design has proven itself.
The more tapered and swept and curved the outline, the more critical the interpretation of that outline becomes. From what I've heard there is a CAD program that can convert the swoopy designs into a corresponding simpler form to do the calcs with?
So far, all I've ever done is my own TLAR version of straightening out some of those lines and plan on the first flight being possibly like breaking a horse that's never been rode.