HI there
As someone who is fortunate to travel on CX in F regularly I don't think that there is a significant difference to be honest ... a marginal one maybe
In the past I've managed to get 2A by phoning CX - though always with the proviso that I might be moved should someone need the bassinet.
The last time I did this was some in mid Feb but maybe CX have changed their policy since then.
But give them a call and see but I wouldn't worry if it's not possible - you will be just fine in 1A ..... enjoy the huge treat that is CX F