Do you understand force vectors? If the lateral offset is the same, then compute the difference in the lateral force vector between a tangentially crossed spoke on a DA hub and a radial one. This will give the difference in tension... of ~0.3%. 22.5mm is the radius of the hub circle, and 280mm is the approximate spoke length for the rims he is considering.
The spoke specs don't matter at all.
The spoke spec does matter is determining their elongation under load.
I'm not sure why you're quoting the hub size or spoke size. These are almost irrelevant now that data has been refreshed in the discussion relevant to the actual wheel build. But even if you choose to present an example for argument sake you need to give two spoke lengths for a comparison.
Consider the deflection of the wheel at a spoke-rim interface point as the Moment around this point. At a radial juncture denote this Moment as Fx, and at crossed juncture call it F'x'. We know x' > x (from spoke lengths). Preserving Moments Fx = F'x' suggests F > F'. So you need greater lateral force to deflect the rim at a radial spoke than you would at a crossed spoke. However the story is still incomplete because the Moment at a crossed will be offset by the actual crossing. This lateral force is also independent of the tension in the spoke as the directions of action are orthogonal to one another. The tension in the spoke is transverse to the spoke and the system is held together with respect to the entire wheel.
You can not quantify the change in spoke tension as ~0.3% because no data here warrants such a claim.