Just got my M10 delivered yesterday. "Used" supposedly, but absolutely pristine -- it, the box/packing materials, and accessories look brand new. Can't wait to use it!
I'm probably not the right one to ask since I haven't used it, but after playing around with it last night:
You can set the backlight to go off after 10sec, 60sec, or stay on continuously. Also, the level LEDs, which show for each channel -12dbFS and near-clipping at -1dbFS can be turned on or turned off.
For Jedi, either keep the LEDs on or off as is your preference. If kept on, I'd imagine you could use those as pretty low key guidelines to whether your levels were ok, without ever turning on the LCD backlight. Or keep the LCD backlight set to go off after 10sec, put the unit into hold and run it that way. On hold, hit any button at all, the M10 will come up saying "Hold On" and won't perform the button function (stop the recording or whatever) but it will light up the backlight for a few seconds (10??), allowing you to check your levels.