Function sweep_profile_along_chain_reported 

pub fn sweep_profile_along_chain_reported(
    profile: &[NurbsCurve],
    path: &SweepPath,
    twist_angle: f64,
    name: Option<&str>,
    anchor: Option<ProfileAnchor>,
    placement_mode: SectionPlacement,
    corner_advice: &str,
    tolerance: Option<f64>,
) -> Result<SweptChain, KernelRefusal>

sweep_profile_along_chain with the requested wall TOLERANCE (mm; None for SWEEP_DEFAULT_TOLERANCE) and the measured bound the build reached, for a caller that carries it on (the sweep features put it in FeatureResult::approximations). The station lane refines its stations until the loft’s own interpolant stands within tolerance of the kinematic sweep’s wall, or the station cap stops it; the report says which.