[RANT ON]
This little bit of salesmanship BS needs to die. Yes, the high/low flange has minor technical benefits that can very rarely ever be realized, but vague claims of stiffness is not one of them.
The bicycle wheel is a beautifully engineered system. It's been quantified/calculated a million different ways. All of the consistent analysis paints the same picture. All things being equal, hubs and spoke crossing do not make substantially stiffer wheels. Mathmatically, there are minor differences but on the road there are none.
For example, a rear wheel with 28 spokes cross-3 drive-side and radial spokes on the other may be lighter than a similar wheel with 28 spokes cross-3 on both sides, but vertical stiffness is unchanged. When torque is applied to the wheel, the math says there's an insignificant amount of deflection in one versus the other, but generally meaningless. Maybe there's some other performance characteristics to discuss, but stiffnes is not one of them.
[RANT DONE]
Enjoy your new wheels. Put lots of safe, healthy kilometers on them and make an effort to welcome/bring new participants along the way.