Long time lurker on this forum and follower of many of your live threads (which are good reads for people to use to prepare for their cruise), but I must set the record straight here.
My group of 7 was in the pergola immediately next to you on the cruise last week. We didn't have a conversation because I am not one to necessarily reach out to strangers to strike up a conversation. I knew you were to my left, because of your previous post about the way you had your pergola made up, weaving towels in the back slats. That was a good idea by the way and you probably saw that we copied it. My wife and 2 kids were on our 3rd YC cruise (Seaside 2020 and Meraviglia 2023). We were most certainly in the YC. Cabin 18025 with butler Wayan to be exact. My sister was solo in 18027 and my two parents were in 18029, both YIN cabins on their first YC experience. On the first sea day both my dad and I woke up pretty early (6:15am) since our bodies were not on vacation time yet. We sat in the unoccupied pergola next to yours and had our coffee. During our coffee, one of the pool attendants (Caran sp?) approached us and asked us "Would you like to sit here everyday?". We said "Sure, but it's absolutely not a requirement". Well low and behold, every morning we woke up before breakfast, and Caran showed us to the pergola he made up for us. He repeated this each day and on the last day we did give him a tip. So the 7 of us used that pergola and the daybed next to it I would say upwards of 75% of the time from breakfast until dinner. Did we venture to the waterpark and leave our stuff there? Sure. But most of the time someone from our group was hanging out in the pergola. And we only utilized a single pergola with 3 loungers for 7 people. I am super conscious about overusing space, so many times there were 4 or 5 of us on the 3 loungers because frankly we didn't need a single lounger for each person, especially small kids. As a non-OS/RS guest, I certain did not expect to get a pergola each day since they are FCFS, but Caran approached us early in the cruise and definitely earned a tip from our group.
As for dinner, we ate exclusively in the YC Restaurant every day at 5:45, with the wonderful Kevin as our waiter. I was pleased to see that they opened before 6:00. We are early eaters and were worried that the move from 5:30 to 6:00 was fleetwide. Like you, I missed the "Deliciously Healthy" section of the menu until day 6, which was a real bummer to realize that was there the whole time.
The group of 6 that were in the other two pergolas appeared to be 3 couples. They sat kitty corner to us at dinner in the YC Restaurant I would say 50% of the time and we saw them plenty of times on the YC Pool Buffet for breakfast. We didn't really talk to them either until the last sea day when they approached us. They mentioned they were on their 35+ cruise and their 3rd YC cruise as well. Now I can't speak for their whole group (since I only chatted with two of the couples), but it did appear they were all staying in YC Cabins. That said, I didn't talk to all of them so I can't be 100%.