I have wondered if I could print a top out of a soft material. They have ninja flex. I wonder if it would deform while spinning🤔
My guess is that the top would work. Centripetal force would tend to keep it round. The concern would be that it develops some vibration/flex modes.
Some of my LEGO tops have more flexible structures than others. When these deform under the abrupt acceleration of spin-up, they can "ring" for some time after release. Especially susceptible to these vibrations are tops carrying much of their mass in spokes with outer ends free to flap and twist.
By structure and material stiffness, metal, hard plastic, and wooden throwing tops are generally much more rigid than my tops. But I can see a hard landing or a jerk of the string exciting lasting vibrations in a throwing top of softer materials.
LEGO precision molding guarantees static balance when all parts are fully seated in a symmetrical arrangement. In addition, tops with parts designed to move under centrifugal force usually self-balance quite nicely. (Might also be true of a flexible throwing top.)
So most of my wobbles end up coming from excited vibrations. Gentle spin-ups can help, but the only real cure is to change the mass distribution or structural stiffness or damping to shift mode resonances away from operating speeds. Problem is, that may not be possible when you're going for a certain look or behavior.