Would you recommend used of hydroquinone cream on a newly healed scar to prevent hyperpigmentation?

HYPERPIGMENTATION. YOU CANNOT PREVENT HYPERPIGMENTATION. HYDROQUINONE MAY LESSEN THE PIGMENTATION ONCE IT HAS DEVELOPED.
No. Mess with that stuff and you risk disfiguring yourself. See what happens, and only try a skin bleach if you really need it. Scars are signs of having lived, and for most people who know you, they increase your appeal. When it comes to healing, natural is likely best.