If you arrive in 2E and fly from 2G, you won't be able to use the 2F lounge. Nor a lounge in 2E for that matter.

But the 2G lounge is quite nice even though as far as I remember it doesn't have sleeping pods. If you buy lounge access in advance, my guess is that they would be less inclined to turn you down because of capacity issue, compared to just showing up there empty-handed.