What’s interesting here is that there appears to be little convergence from different manufacturers towards an ‘ideal’ design.
I suspect that a good proportion of the aerodynamic work on cycling products (frames, wheels, etc.) is mostly for marketing, and isn’t backed by expertise, testing or CFD remotely approaching the level of, say, Formula 1.
The apparent randomness of aero helmet designs maybe reflects this, and also (of course) the relative lack of resource in cycling product design.
I think a key difference is that in Formula 1 there are limits to the types of designs teams can build. To my knowledge that doesn't exist in cycling to anywhere near the degree of Formula 1.
Formula 1 may not be an "ideal" design if you let each team do their own thing entirely. Also F1 car specifications are also designed around their ability to race with other cars.
The reason cars look so similar in F1 is because they are mandated to be that way to a degree. But that doesn't necessarily mean it's an "ideal" design.
However similarly, cycling helmets are designed and tested in wind tunnels believe it or not.
I suspect that a good proportion of the aerodynamic work on cycling products (frames, wheels, etc.) is mostly for marketing, and isn’t backed by expertise, testing or CFD remotely approaching the level of, say, Formula 1.
The apparent randomness of aero helmet designs maybe reflects this, and also (of course) the relative lack of resource in cycling product design.