I understood that you meant the evening already in your first post.
I have spent several days on that platform there at rwy 18 and unfortunately during the evening it always feels like you miss the widebodies that you really want because they choose to depart on rwy 07/25. The ones that choose rwy 18 are always the same like SAA and Lan Chile etc.
During the daytime then, in my opinion there is quite many widebodies that depart on rwy 18 on the day especially around midday when a lot of the US airlines, Arabic and Asian airlines depart. Unfortunately photography is not possible at that time if it isn't cloudy
This is just my thoughts though