Space-weather forecasting requires knowledge of the CME magnetic field strength, orientation, and topology before they reach Earth. However, coronal fields are weak, and the Zeeman-induced circular polarization in the corona is too small for routine CME magnetometry. Neutral helium lines provide a promising alternative, as cool prominence material entrained in CMEs remains observable while its linear polarization is sensitive to magnetic fields through the unsaturated Hanle effect. We investigate He I 1083 nm and He I D3 587.6 nm spectropolarimetry as a diagnostic of CME magnetic structure using forward modeling from realistic MHD prominence-eruption simulations. The models show that the neutral helium linear-polarization morphology is linked to the topology of the erupting flux rope, while multi-vantage observations can help reduce some of the Hanle ambiguities. Recent UCoMP and ASPIICS/Proba 3 observations demonstrate the feasibility of this approach, detecting eruptive prominence material in neutral helium lines up to nearly 2 solar radii. These results support neutral Helium Hanle-based spectropolarimetry as a path toward magnetically informed CME characterization for space-weather forecasting.