Hey there, sorry I'm not often on here until the evening, so only just seen your updates. Yay for the sttn

Looks like you did the right thing there, despite the really annoying start to the day

Yes I wouldn't be afraid to hang on to that CN a little longer - not necessarily every day, but if naps weren't so good for whatever reason, it really can help to avoid OT from a long A to BT, but still get enough A into him to be able to sleep well at night, iyswim? During the 3-2 I remember some 10min CNs, just to get the extra A time in before BT, you may find that can help for you too, occasionally.
It's hard with school runs, isn't it? But you don't have to do it every day, is that right? Is he sleeping a consistent 2h morning nap off a 3h A time, then? By all means try the second nap at 3h15mins, I see you tried for 3h on 26th but perhaps he was UT and so didn't settle. So a 15min push would be a good place to start, see what happens for a few days and then push again if necessary. Would it work for you to move 'official' WU to 7:15am, perhaps, then shift the naps 15mins too so that he can have his pm nap at 3:30 without being OT? I can't decide what I think about his A to BT, that day when he had 3h then after a 2h nap, he'd also had a disturbed, short am nap, so I wondered if he might have had some OT left over from that?? I guess I'd try that 3h 15min second A time for a few days and just see what happens, note it down and that gives us a starting place, right?