This study presents an experimental investigation of flame-wall interaction in ultra-lean hydrogen-air flames exhibiting thermodiffusive instabilities (TDIs), with and without effusive cooling. Flames are generated using a V-flame burner impinging on a temperature-controlled wall, enabling controlled and repeatable flame-wall interaction. The burner configuration produces a clear spatial separation between an upstream stable flame and the downstream onset of TDIs, allowing detailed characterisation of unstable flame-wall dynamics. Ultra-lean hydrogen flames at equivalence ratios Φ= 0.34 - 0.40 are examined, where strong differential diffusion effects arise due to hydrogen's low Lewis number (Le ≈ 0.37). Flame topology and wall quenching are measured using 10 Hz OH planar laser-induced fluorescence (PLIF) from two viewing perspectives, capturing both global flame structure and near-wall behavior. Without effusive cooling TDIs exhibit small but highly stochastic quenching distances, characterized by a broad, right-skewed distribution arising from nonlinear coupling between heat and mass diffusion. At Φ = 0.34, the quenching distance spans δ_Q = 300 - 1600 µm (5th-95th percentile). In particular, the influence of near-wall mixture dilution on flame quenching behaviour is examined using an effusion-cooled segment. With the addition of effusive cooling, the boundary layer is modified and hence the TDI distribution and the quenching distances are changed. The geometry is based on the work of Hermann et al., employing a regular grid of both traditional, as well as porous cylindrical holes with a diameter of 0.7 mm. Representative blowing ratios are investigated, chosen to mimic realistic effusion cooling conditions encountered in gas turbine combustors. This approach enables systematic assessment of the coupled effects of wall cooling, dilution, and near-wall flow modification on thermodiffusive instability dynamics and quenching behaviour in ultra-lean hydrogen flames.