On my folding bike with a 33.9mm seat post, The quick release clamp has become really hard to operate because the brass bushing and the butt of the lever have worn down after 7 years of use. The brass bushing is a really thin plate that's easy to deform.

There's one OEM model replacement widely available but it comes in varied packages, some with a similar thin brass bushing or with a thick plastic POM.

Would the brass bushing or the plastic POM perform better, be more stable under the high bending of the really long folding bike seat post, or last longer?

I assume the POM is easier and smoother to operate, but some risk of it falling apart if clamped tightly.