I stayed here last month and there weren't issues with the lounge being full. Once or twice I couldn't get my preferred seating type (sofa in back versus by the window versus large tables versus small tables near buffet) but even though the hotel was full (and not selling rooms on the Starriott website), the lounge wasn't full.

I wonder whether the hotel has started to sell relatively inexpensive lounge access to locals. This seems to be done at some hotels in Kora, so maybe this place in Japan is copying the idea. They could have a lounge surcharge on regular room bookings (not just suites and room categories that include the lounge) that's priced low enough to attract too many people.

If a lounge told me that they would call me to come back later, I would have reminded them at least once, perhaps about twenty minutes before the scheduled time for F&B to be taken away. If this still didn't work, I would go to the lounge then and insist an either taking food before it went away or some service gesture like appetizers and drinks in the hotel restaurant or bar of my choice (not some horrid all day dining spot) or from room service becasue presumably by then I had spent time waiting in my room for the call. However, in the case of the PG, the lounge is particularly attractive and better views than some of the rooms, so one would still be losing by having happy hour in one's own room.