from an aesthetic pov, there's really no where to go. the cue has a very limited work surface and very much dictates the design. even with today's designs, small elements combine to create longer flowing designs along the length of the cue.
in the older cues from a century or more ago, there's no denying that aesthetics was foremost in the minds of the cuemakers.
probably, a knowledge of those cuemakers' backgrounds might lead you to a better understanding of what was uppermost in their thoughts,,,ie,,,were they formerly furniture makers,,,,,artisan/craftsmen,,,,weapons makers,,,,,before they began building cues????? furniture makers, for instance, i would guess used design with a functional purpose,,,while artisans were all about the art of the cue,,,,and maybe weapons makers brought some functionality of design that made their weapons more powerful.
i happen to think it was purely artistic,,,,like the way lances were embellished for jousting. first came the lance, then came the fancy doodads.