
Disclaimer - my ramblings about geo are just that...nothing for certain and just personal observations not meant to imply anyone else should feel the same way.
I've been riding a fair number of frames the last few years and that has allowed me to try out some geo ideas and see what happens. It's been fun to experiment and since it's mostly been hardtail frames the cost to swap parts between frames hasn't been high which has made taking some risks a lot easier. One thing I've generally known is that I seem to prefer shorter CS and slacker STAs. I feel really awkward and uncomfortable pushed up towards the front of the bike with a lot of weight on my hands.
I also haven't enjoyed longer CS. Lots of people seem to like them so I was kind of surprised that every time I went longer back there I didn't enjoy the experience. The one exception to this is my Krampus where I do enjoy riding it despite the 446mm CS....I'll come back to this later.
I've had some interesting experiences where I've had the same bike as a friend and we've had opposite opinions on how they worked in specific situations....like say steep techy climbs.
I'm 5'11" and wear 33" inseam pants. So roughly in the sweet spot for bike design criteria. I do carry my weight in my upper body more then my lower. I've got scrawny legs and no butt. #SadbutTRUE
Now that I have more data on these issues it's becoming clear to me that the reason I like both short CS and slacker STAs is because it's hard for me to weight the back end of the bike and it's easier for me to overweight the front end. It's kind of obvious now, but it took riding a bunch of bikes to see how my stoke for the bike really corelated to how easy it was for me to get my weight on the rear tire. That also explains why I can ride a rear tire happily up a steep climb and my front end doesn't lift. It doesn't take much of a lean forward for me to keep the front wheel on the ground.
Going back to the Krampus I think the reason it works for me despite longer CS is that it's got a slack 72.5 deg STA combined with a 1" offset seatpost, which really gets my weight back...apparently enough to counter act the long CS.
Figuring this out better in my own mind is pretty useful as it explains why my demos of steep STA bikes weren't positive. Aside from not enjoying the comfort/ergonomics of that pushed forward position I often had issues with rear wheel traction on steep climbs. It's easy to slide forward on the saddle to make the effective STA steeper, but you can't really slide backwards off the saddle to make it slacker...especially on a long front centre bike.
This knowledge will help me pick frames in the future or may steer me towards getting custom frames made if available bike geo diverges from what I want enough I can't make things work with say a 1" setback dropper.
One thing I am still thinking about is why I like really high bars at the moment. It could just be old guy ergonomics, but I am pretty flexible with good core strength so I am wonder if it also has something to do with that upright position also helping to rotate my weight backwards towards the rear tire. I do have a "fleet" of handlebars with a variety of rise options so I really need to experiment with one bike and change the bar height in small increments to see what happens.