Function fillet_edges_variable 

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

Variable-radius fillet/chamfer of a GROUP of edges (§4.9.5), the app entry for tapered blends: each selected edge (resolved by a point on it) is blended with the SAME radius profile radii — a list of (edge-fraction, radius) stops in [0,1] — applied along that edge’s own parameterization. Edges are blended independently (no shared-vertex corner rounding; a variable-radius star has no single tangent ball), so this is the tapered counterpart of fillet_edges for the constant case.