I'm not sure that there is one answer to that question. While on our audiophile side we love simple philosophies of how reality works, the designers spend most of their time mitigating existing issues. Could be durability, could be about certain resonance at certain frequency as a function of the dimensions of the driver. I intuitively would want to say that big perfect flat is the ideal target, one simple wavefront from an ideally stiff but light driver is the dream after all. But as that doesn't actually happen, different people with have different priorities and take different routes to solve their issues while trying not to add too much extra mess in the process.
You might want to reach out directly to the brands, some will not even engage, but some are fairly happy to share some information. Obviously, it might work better if you present yourself as a reviewer and a fan, than as someone who might compete with them one day ^_^.
And whatever you figure out, as a curious amateur, I'd like it if you shared some with us.
