Going on 3 years now with my CX as primary display on PC and no signs of burn-in yet. Then again, I've also altered how I use the primary display to reduce the chance of burn-in. For example, all icons and permanent display elements like the task bar are on the side monitor which is currently still an IPS panel.
In another 2 years I might get a new OLED and move the current CX to be the side monitor. At that point burn in won't matter to me as it's the side monitor, so it'll be interesting to see how quickly burn in might set in once I do that. Alternatively, I could go to a 3 display setup.
Ooof, having an LCD next to an OLED really just accentuates how bad LCDs are compared to OLEDs in most things.
Regards,
SB