I’m curious on how to do this too! i3 + tmux is one heck of a win on these R01 units ( and became my personal favorite work around, so far… [ again i3 is a insanely low resource using tiling window manager ] ). i.e. - i3 was right up my alley for just the right learning curve and feature sets, same reasons I snagged a R01 and this unit.
All this being said, please do post if you can determine the proper kernel line that will power save / blank the main screen.
Side note: Bonus points if you or anyone else has a howto for compiling in on these R01 units additional kernel modules. I’ve a simple USB → GPS ( looks to be a serial adapter in lsusb with missing driver/kernel modules ) along with a simple USB → 10/100 adapter that again is seen with lsusb yet, no module or functionality.
(edit) - I3 for uConsole 
##Check out this cross post for i3 pointers