Overlapping bands of iso-asymmetry values across a₁₁, a₂₁, and a₂₂ demonstrating the drastic reduction of degeneracy in (|ℛ|,β) space for a co-aligned quadrudipole when using ℓ = 1 and ℓ = 2 oscillation modes simultaneously. The white line, dashed line, and dashed-dotted line respectively indicate the analytical solution corresponding to the measurement of a₁₁, a₂₁, and a₂₂ from Sect. 3.1. The width of colored bands indicating typical uncertainty on the measurement of the asymmetry parameters is chosen to account for the finite data frequency resolution of Kepler 4 years following Sect. 4.2.