I was Googling around for an answer and actually found a reply on this forum from a Pimoroni staffer.
We haven’t subjected our displays to anything more than 30 second intervals for tens of thousands of cycles- so we just don’t know what might happen.
I suspect nobody has pushed a Papirus to the limits long enough to notice any drawbacks and the same applies to our displays. You may be fine, but there’s no telling for how long.