Sounds like a great project, but if you let the curves drift too far from exact symmetry you’ll end up with a mess. Try writing a script that enforces a central axis and mirrors every control point – that’s the only way to keep the set looking tidy. If you want a quick visual check, generate a single icon, rotate it 180°, and overlay; any misalignment will pop out immediately. Good luck, and keep the tolerances tight.

Nice, just make sure your epsilon is stricter than the screen resolution, otherwise you’ll still see half‑pixel fuzz. If the curve still feels off, check the order of control points – a misplaced “knuckle” will break symmetry before the math even notices. Good luck.