I dunno... Perhaps I have been in the two-hand or 'spey' casting thing too long or perhaps long enough to know that a line closely approximate to correct should be able to be cast fine by any given rod. This pseudo-science and new thirst for the magic bean through calculations, measurements, Euclidian geometry, etc. Has me puzzled at best. More and more I believe that this little corner of the sport is being over-complicated by people giving advice based on little experience, dogma relating to strong personal preferences, and for a disregard for the joy of just going out there and casting. We used to get by with windcutters just fine, then better lines came along. Good. Then came the pseudo-science of running-lines and matching heads which at first was fine, but has now evolved. or devolved into such a miasma of obfuscation that it is a wonder that people are even not more confused. Long ago I simplified my approach and fishing gear, and it paid off. I spend less or no time fussing and futzing, and just cast and swing. Perhaps there is a lesson here in simplification, time put in on the great rivers, learning by having your a$$ handed to you, and a bit less attention paid to marketing hype and the new 'magic bean' rod, line, vortex technique, etc.
Then, somewhere in the mix of learning and time, things simplify themselves, and we may pay less attention to the noise, and more time just enjoying the cast and swing, regardless of the line, rod, matching hip pack, running line para-physics, etc.