Cathay Pacific Asia Miles - Premium economy - middle seat arm rests go up?

I've seen some indication that only the middle two seats' arm rests in premium economy can be raised. That is to say the arm rests between seats E and F. Is that correct? We're thinking of flying premium economy with our two kids and taking a set of four middle seats.

Correct. Not all armrests go up.

Correct. Not all armrests go up.

That's correct. But do any of the Y+ armrests on a 77G/77H go up?

I think it's going to be the same with what you get on regional J seats. All pax needs that little glass space :p