DIY Modular Video Light

I've been wanting to build an LED video light. Sound's simple enough, but I like to complicate things slightly. So I want to design a modular system that uses a single custom designed PCB, but that can have many copies of that custom designed PCB in one enclosure to make a bigger "panel-style" LED video light, or just one or two of them for a smaller light.

Also to complicate things further, I want the ability to choose either 12v or 18v power (without wasting a lot of power in a big dropper resistor for 18v) so that I can use an 18v LION powertool battery to power a portable version of the light.

I also want to design & create a modular case system that can be printed on my 3d-printer (max 220mm x 220mm printbed capacity)

These are the 2 main files for this modular system, namely the base and the lid. The lid will need to be printed in Transparent (best) or White (more diffuse) filament, the base can be printed in whatever colour floats your boat!!!

I've made a series of v