[megous]

You'd need to limit the CPU operating points or offline most of the CPU cores to get lower max power consumption under load. 5W is too strict for Orange Pi 5 Plus. And of course forget nvme if you want predictable low power consumption. nvme alone is 5-10W load. The board itself can run under 5W, but you'd have to carefully consider what peripherals you can use and how.

See https://xnux.eu/log/088.html