My approach to bike fit is to establish my "triangle" - BB, seat and handlebars, then rotate that triangle forward or back around the BB depending on how I plan to ride that bike. My cruiser-ish geared bikes get rotated back the farthest. (And may have CX-style interrupter brake levers on the bar tops.) My fix gears get rotated the farthest forward because I may be spending long stretches of road going upwind in that gear that is now too big. Getting really low is the only way to give my legs a break.

This approach means my KOP varies a lot. So does seat-bar drop. And seat setback. The faster bikes have me putting real weight on my hands. (And I lost the ability to ride hard enough for long periods years ago. Age does that. So using pedaling torque to relieve my hands is now a distant dream.) I take handlebar shape and position, brake hood shapes and positions very seriously. And I completely ignore what people might think of what I come up with.

I get to do the "triangle rotation" very easily because I have CAD skills and a CAD program. I have all my bikes, including a lot of my past bikes, drawn up. I can easily open up that drawing, pull up the bike I want to modify, draw the triangle, rotate it say a degree and see what that does to seat setback, stem requirements, etc. Fun!

To me, the goal is to find the "triangle". Different for all or us. I lucked out. (Or perhaps had a mechanic with good eyes.) The mechanic at the bike shop I worked at my racing days and one of the salesmen talked me into buying the last year's race bike in the basement. A high BB, steep, tight criterium bike. I was a long distance and major hill/mountain climber. That bike fit like a dream! The stem was too short and I compensated by slamming it. Worked. (I was 24 years old and strong, Riding all day with my weight on bent arms was something I could. Now I need my arms straighter or I simply wear out. I need longer stems than the old 130mm standard on most non-custom bikes. Those stems aren't slammed any more. I have a pile of old shorter stems with dents in their throats!