This study investigates the influence of normal metal thickness on the Larkin-Ovchinnikov (LO) instability in superconductor/normal metal heterostructures. Bilayers were fabricated using a 22 nm-thick Mo2N layer, with varying Pt, W, and Al thicknesses. The samples exhibited a critical temperature of approximately 7.5 K. The LO instability was characterized through current–voltage curves, which relate the maximum vortex velocity to the recombination time of normal electrons into Cooper pairs (τ). The results reveal a significant enhancement in vortex velocity at moderate and high magnetic fields when a metallic layer with thickness exceeding the coherence length is added. Furthermore, a direct correlation is observed between velocity values and the thermal conductance of the metal, indicating a contribution from phonons and heat dissipation to the maximum achievable velocity in the heterostructures.