A few observations from a guy who's been riding a long time on what works for him. I'm a long, lean, skinny person. Not strong. But I have always liked going fast. (That "fast" has changed over the years. I raced my 20s. Fast at 70 is a LOT slower.)

I learned long ago that I have to have a near flat back if I am to go either fast or upwind. That has never changed. The day I cannot will be the day when I have to settle for biking being substantially less fun. So, I set up all my bikes to be comfortable with a big forward lean. And, for me, the best is with a very long reach to the handlebars, my arms with enough bend to be good shock absorbers when I want to ride relatively upright but less than a 90 degree bend brings my back to near horizontal. Now, this means real weight on my hands all the time. Yes, I could slide my seat back and take weight off my hands but that either closes up my abdomen/thigh angle or has me riding more upright. Keeping the angle open has always felt like better oxygen flow.

So I am content with my position BUT, it does mean that getting off the bike for a long period means there is a shock when I get back on. My arms and hands! They have to do real work! And it means that I need to pay real attention to details around handlebar bend, rotation, brake lever shape and location. (New setups - I go for rides without handlebar tape, just enough electrical to keep the cable housings in place, and bring all the wrenches to adjust that stuff. No tape means a) the work is easy while on the road and b) since the is no either grip or padding, any errors are magnified. Once the locations are close, I tape with cloth tape wrapped from the bottom so I can further fine tune only unwrapping half and cloth tape re-wraps and sticks nicely.)

All this said - seat height always comes first. Get that and your quads, etc, right before putting in "cockpit" effort beyond making the bike test-rideable.