Evaluation of derived CME parameters across different observer configurations. (a) Errors in center-of-mass velocity (Δv_CoM), shock-front velocity (Δv_FRT), latitudinal position (Δθ), longitudinal position (Δϕ), and total CME mass (ΔM_CME). (b) Ecliptic slices of the reconstructed electron density for the ground truth, a three-viewpoint configuration, a halo-CME setup, two side-on viewpoints, and a far-side configuration. Observer positions are indicated by blue arrows. The most accurate reconstructions are obtained when observers are located within 100° of the CME. However, the propagation direction can still be reasonably recovered even from far-side observations.