Recently, I made an Arduino UNO that I showed to have better switching characteristics than a commercial board. It was a great project to help me understand how seemingly inconsequential routing practices can lead to issues down the line.
I could imagine small companies that rely on these boards and that also have their fab and sourcing pipelines set up would be able to easier source these themselves. Just have to generate the Gerbers (fabrication output format most manus need) and then send it off as part of a larger order, etc.
Especially if you're able to replace certain small/passive components with those you already have in bulk, it could be a potential cost cutting measure.
Just a guess though.
For my case, they'd be useful if I wanted to know how certain subcircuits are designed or laid out.
wow, I've been wanting a "PCB design system" like this for such a long time. I've always found it stupidly hard to just take an existing working board and tweak it.
http://www.simonjjones.com/#/posts/golden-arduino
Especially if you're able to replace certain small/passive components with those you already have in bulk, it could be a potential cost cutting measure.
Just a guess though.
For my case, they'd be useful if I wanted to know how certain subcircuits are designed or laid out.