Thanks a lot — glad you like it! :)
The roundness of a shape definitely affects the final result, but the main issue when aiming for low-poly geometry is actually something else: there's currently no implementation for simplifying the exported mesh based on a geometric error tolerance.
What you'd need is an additional step during export that merges similar or flat triangles to reduce the overall count. That’s not implemented yet, but it’s something I’d like to look into for future versions.
Cheers,
Sascha