14mm Copper MCPCB for XM-L's anywhere?

Etching out the dielectric layer and filling it with solder would reduce thermal resistance significantly. That dielectric layer is like an insulating blanket. If we could solder directly to aluminum it would work great too, maybe not quite as good as copper but still very well.

So your sayin it probably would be worth it since I already got the 5pk of copper PCB’s and I could just fill the gap with solder? Real solder or solder paste?

What would be the easiest way to remove the layers? I have some PCB etchant, do I need it for the job?

Note this is what I use PCB etchant for, never actually etched a PCB:

Darkened the CPM-M4 blade on my Spyderco Gayle Bradley.