geometry noob here, but from what I understand this high STA also makes the effective reach quite a bit lower? I usually run my seat as far forward as I can, even with the short reach bike I got, so this actually seems like it could be quite interesting. Feels like with my extremely fat ass the extra presure on the front helps too. TBH this bike seems pretty interesting to be.
Reach is most interesting when sprinting or climbing, ie generally when standing up. When sitting on the saddle, then top tube length is the more important measurement.
But generally seat tube angle and saddle position is most important so you get a good position towards the pedals/cranks. So you don't kind of pedal forward, but rather downwards. Then when you know your approx ideal seat tube angle it is usually easy to calculate approx what total reach you want/need. And i usually think toptube+stem+handlebar reach. In my case i run 551+70+77=698. This is not really 100% true, since with a steeper seat tube angle i may back up the saddle more, which would mean that same top tube length would equal to longer total reach.
My bike today does have 73.5deg seat tube angle with zero offset seatpost and saddle slammed all the way forward. To get kind of optimal position without slamming it forward i would need at least around 74.5-75deg angle. Different saddles have different rail positions also, so another saddle would be possible to move more forward than the one i use today - but the one i use is easily best for my butt today 😅
