I had what is probably a stupid idea.
I'm not realistically considering doing this, but my enquiring mind wants to know if it's not as dumb as it first sounds.
Say I have two stacked boards that need to share a common power and ground circuit. Assume that metal standoffs will be used to assemble the boards into the stack, with screws to fasten. If I were to have unmasked annular contact areas around two of the mounting holes, and one was routed to ground and the other to power, would that be workable?
There's a saying: "if it's stupid but it works, it's not stupid". Just wanted to find out if my idea fits the proverb.