It's hard to say exactly. This IR mirrors that of the scoreboard that retained after watching football all day back in October (in fact, some of what remains could be traces of it).
Regarding Netflix, it was first used with Oppo's on-board app about 4 months back, but once I realized there is a lack of screensaver (it would only dim the screen after 5 minutes), I switched to the one housed in Panasonic's SmartTV apps. There is a screensaver here, but it's impossible to engage the pixel orbiter for that extra layer of protection. That one has been used for at least the last 4 months, so the nav bar would never be on the screen for more than 5 minutes at a time. During the Oppo usage, I don't recall there being any severe abuse (where it was left on pause for more than 5 minutes), but it almost seems like there's a cumulative effect taking place here and between its appearance on-screen, the phosphors are not refreshing sufficiently. It will be interesting to see what happens with Netflix on Roku.