There should be liquid, not air, cooling the bond wires. That would be much easier and more efficient than taking the heat away with copper. I agree to putting solder blobs on them.
If it is de-domed, and the space in front of the led filled with a clear liquid, it will cool both the diode itself and its bond wires. Forced circulation isn’t necessary there, as the heat will cause convection, with or without boiling.
With a mirror reflector, a clear liquid won’t effect the optics, except to reduce reflection, probably more help than problem. With a double convex lens, it will increase the focal length, which needs to be corrected for in the design. But aspherics I have seen have flat back sides, so the effect will be small and in the opposite direction.
I didn’t catch the limitation of the optics. The bigger the lens or mirror, the brighter (and smaller) the spot.
The optics are the large Defiant Super Thrower heads with deep reflectors. im not sure how LEDs would react over time and how they run though submerged in a liquid. it woudl have to be an oil-based so its non-conductive.
I used 91% alcohol. It didn’t conduct significantly but it softened the epoxy I used to hold things together. There are commercial indoor lights filled with silicone oil. I see that you don’t want to take chances with long term degradation, but I really think that is part of the way to get the most current through an led without its burning up. Dedomeing would then be to enhance cooling, because the optical effect of the dome immersed in silicone would be small.
I got extremely good throw relative to the total light with a stage lighting Fresnel lens, but the chromatic aberration is pretty bad. There is a lot of blue and orange around the edges of the spot. It could have been reduced some if I focused it better. The lens has such a large diameter to focal length ratio that it focuses most of the light from the led. There is much more light in the spot than with usual aspherics.