The article at the end mentions they suggest dd as alternative for MacOS (due to Unix user space). It seems the balena -> rufus decision is about the easiest-onramp Mac+Win-portable option, for those uncomfortable dropping to low-level device-writing CLI tools in their current system.
Side-note: Last time I was on a friend’s Windows I installed dd simply enough both as mingw-w64 (native compiled) and under Cygwin. So for Windows users who are comfortable using dd it only requires a minor step. When I once used WSL devices were accessible too, but that was WSL1 (containerized), whereas WSL2 (virtualized) probably makes device-mapping complex(?) enough to not be worth it there.
I hadn’t even heard of the underlying protocol NNCP yet, and it seems to solve out of the box several things I was trying to do in some of my own hobby-projects. I’d been battling with automating and integrating Tor/I2P, Openssl, Tox, GPG, Wireguard, etc. If NNCP lives up to the hype it will be a big shortcut, when I next get time to work on stuff :-)