Question 3D scroll effect on text

Currently I have a dropdown where the drop-down is a masked Scroll Rect. I want to add make the middle bulge out as if it's a spinner, like in this photo:

What's the best way to achieve this?

I could potentially do it with a custom shader on the material of the mask of the scroll-rect that just bends the UVs, but from what I can tell that would involve using a GrabTexture which seems a bit excessive? I tried to get a simple sjader that flips the uv of the texture working as a test, but it only seems to work in the scene view, not the game view, and I couldn't accurately find the bounds of the RectTransform in the uvs.

Another approach would be rendering it in 3D to a rendertexture then displaying that, but that seems even more excessive than the render texture approach.