I did indeed once work from the DUB lounge for 8/9/10 hours (WW was there that day as well) and initially they told me I would have to leave after 3 hours and check-in again but I think she realised how silly that suggestion was as she was telling me and I just stayed and worked and worked and worked and worked.
not something i'll repeat in a rush but possible (and I have a reputation amongst the CCR staff that I am the one who's always working in the Boardroom so I think I am doing something wrong from everyone else on here when it comes to lounges......)