You bring up some interesting points, Latios. I would like to investigate this subject further.
For prolonging life, CRTs should be turned off, hence the whole thing with preventing burn-in.
In my experience, turning off a CRT at night and turning it on again in the morning over the course of several years increases the ‘boot’ time of the monitor. Have you not seen this anomaly? Granted, we’re talking dated technology.
LCD's don't suffer this, and with an LED type, it doesn't really matter. But if you are power conscious, LCD's actually eat more power if they display a predominantly dark image.
A link to this sort of data would be nice, however, I can only speak from personal experience. Heat generated from a LCD’s backlit screen can take an exceptional toll on the LCD itself… such as… running a screen saver.
I look forward to your post decompiling this enigma. It is a question that has haunted me for years!