Function fillet_edges_variable_vertex_radii 

pub fn fillet_edges_variable_vertex_radii(
    solid: &BrepSolid,
    edge_points: &[Vec3],
    edge_names: Option<&[String]>,
    vertex_radii: &[f64],
    chamfer: bool,
    name: Option<&str>,
) -> Result<BrepSolid, String>

The natural per-vertex user model: radius vertex_radii[i] at chain vertex i (in CHAIN order, starting at the free end of the earliest-selected edge), smoothly interpolated along the chain (monotone C1 — every vertex radius met exactly, no overshoot). Requires exactly one radius per chain vertex (edges + 1).