I have experimented recently with a more forward saddle position on my Parlee and it immediately resulted in sore wrists which tells me too much weight was on my hands. I've been using the Steven Hogg method lately:
https://www.stevehoggbikefitting.com/bi ... oad-bikes/
Even though people now say that KOPS is arbitrary and irrelevant, my setback ends up basically right at KOPS. So, it's not like I have an extreme setback compared to traditional methods.
As for saddle setback... it is the distance from a vertical line through the center of your bottom bracket to the tip of your saddle.
I've always wondered about using that measurement. Isn't that only good for one saddle. A different saddle could have a shorter or longer nose and you could easily be off by a centimeter or two.