As a builder with many years experience the truth is spining a rod is at best a over exaggerated phenomena.
Yes there is a spine, but building on or opposite of it has little bearing on rod performance, no one fishes a rod on a perfect 180* plane.
Building it on the straightest access is what matters, usually putting the greatest curve upwards to offset gravity so to speak.
Not!
If the spine is not in the correct position "Pointing Down" you risk breaking it.
Regardless whether your Guides Point up as in Casting or down as in Spinning !
Even Parabolic, Nano Toray Carbon & Helical, Rod Blanks are Splined
Simple Solution is ?
Talk to Any Rod Manufacturer and ask them.
They are, "Rod Blank Manufacturers"
With many more years experience then any of us !!!!
Tight Lines
Dan