Why does Armbian include both include ifupdown AND NetworkManager by default? I'm not aware of anything that ifupdown can do that NM cannot and ifupdown doesn't have a TUI/GUI like NM so as far as I'm concerned ifupdown is just clutter that causes config clashes and boot delays. Isn't it time to strip ifupdown from Armbian?
On a related note, I've never got any of the (ifupdown) network config options in armbian-config to work.