Precision and instability limits of vortex-based particle translation. Left: Horizontal (x-axis) motion. Right: Vertical (z-axis) motion. Blue/green dots: mean position (n = 7). Dashed line: ideal target. Red/orange squares: ± standard deviation. All axes in cm. Data show high x-axis precision (σ ≤ 0.03 cm) and pronounced z-axis instability (σ = 0.10 cm), defining the operational boundary of vortex fields.