Question/sugestion: why didn't you mount the leds on the ceil of the cabinet , placing the warm part outside the growbox for more head space ?
Will be very interesting to watch this thread (again).
I wanted this box to flexible.
My plan was to get the same style recessed lighting in daylight and make a veg bar so I could swap them out. Cutting holes in the top would limit my flexibility in that aspect.
The body of the fixture does get pretty warm, not burn your finger hot, but pretty warm by the end of 12hrs, but overall the cab is really cool. The heat that comes off the fixtures is blown toward the vent, it doesn't really circulate around the cab.