I doubt the problem is the spinner.

The backplate is bowing, because the thickness of the prop or hardware is not right for the setup.

There should be NO "rearward" pressure on the outside of ANY spinner what-so-ever. That is what causes "bowing".

All of the pressure should only occur on the inner part around the prop shaft.

I've seen a lot of newbies do this with thinner or thicker props installed than they should have used.

Placing a spacing washer, or using different hardware solves the problem.

e.g. a spinner with a central locking screw, may not bottom out in the central shaft holder... so the newbie overtightens it because the screw feels "loose"... what is happening is that the out part of the backplate of the spinner is moving rearward with the force, which will end up damaging it. A longer central screw might fix this...

Even the best spinners can and will bow out if they are incorrectly used, and even the worst spinners may work well if correctly set up because spinners don't really do much.... mechanically.