Given that the technology of eink screens make it so that even during normal usage the power requirement is kept lower than other kind of displays, when it is advisable to completely shut-down the device instead than putting it in stand-by? I'm asking this for the sake of device (and possibly battery) health and power consumption.
As an example, I usually use stand-by, and this seems the handier solution when I use it multiple times in a day for many consecutive days, but maybe not when, i.e., I don't use it for a week or so. Or in other words, is there a time limit that marks the border between advisable poweroff or standby?