Yeah, I was surprised when I received mine that it doesn't have an "off" mode, by default. Granted, the battery lasting over a week is fine, but considering I only use it a couple days a week, it feels a bit wasteful. I might modify it and add an inline power switch. Who needs RTC anyway.
Settings -> Power -> Power OFF seems to be a real "off" mode. I turned it off like that a month or two ago and put the flipper back in the box. When I turned it on just now to get this update, battery was at 82%.