The hammock effect of a b17, which is why nose up helps, is not applicable to Cambium saddles.
Cambium saddles can be dead level.

After reading the text and scrolling down, I'm Like Crap! That is a Freaking Gorgeous Bike ! Love the melding of colors!

Got my first decent ride in

Bike feels great, can feel the stiffness of the slx, steering and handling is quick
despite stiffness handled by 6 miles of gravel loops really well, with 27mm FMB tubular at 105psi
Bike wanting to go, ended up with messages from my garmin about exceeding aerobic levels me being out of shape did not help
Drive train works great, as always need to figure out which set of gears to use, defaulted to middle (42) chain ring for most of ride, dropped chain so need to fine tune front derailler limits
over all positioning worked well, will tilt seat down a bit, as there was pressure when in the drops
First time with a Brooks Cambium seat... C15 carved. Worked well. but you don't slide on these at all so to reposition need to stand on pedals and move

Smile rating :D :D :D :D :D :D :D :D :love::thumb:

Why am I not even a little bit surprised?

Yup! De Rosa = smiles! Good first ride report. Minor adjustments are par for the course.