B787 - CAC inoperative in flight

[Piloteprive]

Hi guys,

Prior dispatch with 1 CAC inop, MEL states that the airplane must remain at or below FL350 if crew rests are occupied.

1 CAC inop after dispatch will not trigger any ECL only a STATUS MSG. Officially, you can disregard the MEL and fly above FL350 with the crew rests occupied.
I wonder why we have this altitude restriction in the MEL? I heard different reasons but i couldn't find any information on paper in order to take proper action if a CAC becomes inop in-flight with crew rests occupied.
Any idea on that ?

Thanks

Max