Final Gathering attempt. 1 M photons, Photon Search Radius: 0.5. Caustic Search Radius: 0.75, Max photons = 500. Could be better, but I am satisfied to get some improvements

Photon map for indirect lighting. 10 M photons, Radius Search Radius: 0.5, Max photons = 500

Photon map for direct + indirect lighting. 10 M photons, Radius Search Radius: 0.5, Max photons = 500

First attempt, photon map is working, but buggy