I have an application that is height restrictive, and ideally I'd like to place several (not just two) tinyduinos next to each other.  Is it possible to have an intermediate ribbon connector board, so that the lines go through the middle boards, rather than just one at each end?  IE the boards are laid out in a bus  Can a shorter ribbon cable be obtained?

I like that idea. Either two connectors or possibly an IDC connector for more heavy duty ribbon cable. Could make a bracelet.
I wonder whether IDC Hirose connectors are available. Then adapter boards wouldn't be required at all.