I see your point. But my point was to have much stronger electro magnets by higher turn count. There is not much space in a 27N30P compared to the 18N22P. Combined with the hallbach array, it can output higher torque. There are also stators for MC generators in 114mm OD, but usually they are quite narrow. I would like to have two 35mm ID bearings rest in the stator itself.
By the way, nice link to the video of that hallback array. I was thinking to hold the magnets in place using kevlar or glass/carbon fiber, Still the magnets must be mounted with epoxy.