Forget translating his bio-mechanical take which is believe is patently false throughout...e.g.:
Cyclists should not be predisposed to injuries/conditions due to hyperpronation/hypersupination (flat arch and high arch respectively) because that mechanism exists as a "shock absorber" in walking and running.
Above flies in the face of all convention when it comes to pedal stroke and fit and the thousands of cyclists that have resolved knee issues through their feet. As discussed, cycling isn't anything like walking or running biomechanically. I know many athletes who couldn't survive without custom orthotics and even alleviates foot pain in their dress shoes.
Anatomy of feet varies greatly.

Having the arch supported to prevent pronation is critical to knee health. Arches that collapse (for those with flexible feet in particular) during pressure to the pedals, causes the knee to skew inward and places pressure on the medial ligament which by repetition can be inflamed and injured over time. This is widely known among even average fitters. So adequate support of the foot is key to a good pedal stroke and avoid knee issues in particular.

My intention wasn't to debate biomechanics. Its really irrelevant as the jury isn't out on cause and effect as much as many would like to take issue with it. Point is general discussion about footbed or insole options. Thanks.