I have been playing around with the I3 window manager and its great if you can get accustomed to using hotkeys. At the moment I am running I3 with chrome with 3 tabs, keepassxc, 2 terminals and gst-launch playing video at a flat 2gb on my xavier nx. I have 8 gb total so I have not needed the extra ram so far. This is better than LXDE from my experience. It seems like a great X baised window manager.
This could be a great option for the memory limited nanos
It’s in repos so “apt install i3” gets the base instralled
FYI: Ubuntu seems to use “Windows Super key / mac options key”