I was wondering if with single layer metal PCBs, can the PCB be built so that 1/8” of the border around the edge of the PCB and the mounting holes can be free of copper, soldermask, and Tpreg so that only the exposed aluminum baseplate is there? This exposed aluminum baseplate would then serve as bonding areas for other metal objects that will contact those areas. It would look a lot like the figure I screen shot captured from your website shown below:
