You should be able to cut the UV time down to a second or two, before you get problems with the stuff starting to melt from the radiative heat, even if you use

You should be able to cut the UV time down to a second or two, before you get problems with the stuff starting to melt from the radiative heat, even if you use a strong fan to cool the surface. This is worst-case, and I do think you can get away without a fan, but there might be edge cases.