I sat on the row 75. Was told by the FA to use the loos in front of us (thought they were for WT+ and the rule strictly enforced?) and then later when I walked up to the galley, they ushered me to go downstairs to see how it looked like. Didn't go to the aisles as people were sleeping but there was a handy area behind the cabin, where the toilets were, did some squats there and scared the hell out of a downstairs FA that walked in. She then snapped at me when I started to climb the stairs back and I almost ran. So I got the impression things allowed for passengers depend and we were lucky

The little back cabin was not as peaceful as you would have thought. The galley was right behind and the toilets (for all upstairs WT's) right in front of the cabin.