Hi, I'm already working with 3d printed foot orthopedics and am skilled in 3D scanning my own or others' feet, manipulating the model in 3D, and then 3D printing a device, either out of hard plastic (nylon+carbon fiber), or flexible plastic with long flexure life (polypropylene or thermoplastic elastomers like polyurethane). I have an enormous and high-quality 3D printer, the BCN3D SigmaX, which can print on a bed the size of TWO 8.5x11" sheets of paper SIDE BY SIDE! :D
I would be happy to model something around existing 3D scans of my own foot (or yours if you havea scan), then modify it to extend my height, and then 3D print it with an infill microstructure that gives bending compliance (i wouldn't want a rigid insole! OUCH!) with the right material (PP or TPU as mentioned above would be good, or maybe a blend-composite of nylon and thermoplastic elastomer)
Needless to say, I'm expert in printing even the most complicated geometries...as something that conforms to a foot with a special internal microstructure will be. Others may be able to make a shell model with a decent shape, but they are probably not doing their PhD on metamaterials with variable bending compliance like I am! B)
By the way, I've a master's in polymer engineering and am working on my doctorate. Who knows, I may like these inserts so much I start wearing them! :D
Thanks,
Caleb