On the topic of LPM/LPS - having an LCD display completely contradicts the idea of Low Power Mode. Real low power is possible only on displays that have each pixel emitting the light by itself. All LCD rely on back lighting which can be only ON or OFF for the ENTIRE screen. I haven't heard of phone displays implementation of Local dimming as on some (quite expensive!)TV sets. So yes, having the clock and notifications etc. always on is possible on LCD screen, but battery drain will be nowhere near the LPM on AMOLEDs. It just do not make sense on LCDs.