[quietpain]

   First, I think it would be a great idea for any future Single Board Computer or Router designer -- to design their product such that it will work with any power supply from 5V to 12V (assuming that the power supply can provide enough amperes at that voltage).

Devices that do that have been available for 10+ years, e.g. the OKI series: https://www.mouser.com/datasheet/2/281/oki-78sr-56393.pdf

It's about the size of your thumbnail, costs around $5 and takes input voltage up to 36V

These are my go to devices when I'm installing something in an old device, e.g. adding bluetooth to an old amplifier.

edit: handling more power would require some more space but isn't exactly rocket science.