OS happens when more happens in the environment than LOs can deal with. It presents differently in different babies and at different ages. Some show tired signs, but won't settle for sleep, or do but only have a short nap as they sleep to cope with the OS but haven't had long enough A time for a long nap (which might be what happened today) In younger babies they can get v upset, screaming etc., others just get "wired" wide eyed and won't settle or take longer to WD.
Reading your activities and WD, though, I think you're getting a good activity balance already and a good WD.
Could the fussing and shouting be a call for attention/interaction from you rather than a sign of boredom with the activity or tiredness? I seem to remember my DD getting v shouty around that age, especially when we were interacting with her brother not her!
As Lindsay has said, I wonder if he is more spirited than touchy and needing stimulation and possibly longer than average A times but then also harder to settle and needing your good WD too (which you have in place).
Lindsay has already suggested pushing A times & I would agree with this. You are getting UT naps at 2hrs and a couple of days ago you got an OT nap but successful re-settle around 2hr15. Sometimes when you push A times it takes a bit of time to settle in.
I would agree with Lindsay to keep adding to your first A time gradually until you either get a long nap or a short nap that you can resettle fairly quickly (within 15mins)
Some babies increase their A times as day goes on so need a longer A time after a good nap, but this also means that they can cope without a reduced A time from a short nap. So I would try holding same A time if you get a short nap and increase it a bit if you get a good nap?
A times increase really fast around this age, and it sounds like that might be what's happening here, no sooner do you catch the sweet spot, then he does another increase!