I developed a cunstant current led driver which could drive at least 4 led tools, has a variable input voltage from 9 to 36V and in the end only consists of a transistor a zener diode and some resistors. I bilt it using smd parts and would like to incorporate it in the frame. Unfortunately I still did not have time for that but I think it would be an optimal solution. The connectors to the leds should be pointing inward to the frame and the power supply connector outwards.
Btw. thank you for sharing this super useful design.