Been there several times this year. The self service restriction is linked to covid measures still in place in Italy, not unique to this lounge. When it first reopened (summer 2021) there was indeed no agreement in place but I have used both BA CE access as well as Priority Pass/Lounge Key access during 2022 several times. Was never restricted on alcohol when I was there and the food was easily the best I have had in any lounge so far (baked pasta, fresh buffalo mozzarella, Parma ham and other cured meats, grilled med vegetables, savoury artisanal breads, fresh Neapolitan pastries etc).

also never had issues accessing and/or finding seats.

they may have put further restriction now due to volumes/being extra busy.