Using World Space Render Mode
This tool is designed specifically for world space UI used with a Canvas in Screen Space render mode, so camera perspective does not affect it. But as an additional feature, it also supports billboard UI that is rendered using World Space render mode.

The most noticeable difference between Screen Space and World Space is that World Space render mode often uses a larger scale, since screen size units are usually larger than world units. Because of this, you may need to scale your UI elements down.

However, if you use proximity based scaling for the element, the scale will be calculated automatically, and you can adjust the World Space Scale Render Factor instead. See the 2. Pinnr Demo (WorldSpaceRenderMode) scene for an example.