Well I can tell you my thoughts, with the caveat that you're getting far better naps than we are at the moment so you're probably more sorted than we are!
Ok so first A time is 1h 45 and you get a 1h nap (today, at least), then he did 2.5h A time and napped for 2.25h! That's a lovely nap, did he wake up happy and refreshed? I would have thought that your 1h first nap was a little UT, have you tried pushing his first A? Just that if he can do such a longer A time later in the day and nap well then he could probably stretch that first one a bit? Third A time was less, just 2h after that long nap, but makes sense if you're aiming for a UT CN. The missing piece for me is then the last S time, ie BT? Can't find that recorded anywhere! NWs before midnight tend to be OT which might be accumulated during the day or a too long last A time, do you have a feel for this based on how he's acting? I would expect he'd need a shorter A time after the 30min CN compared with earlier A times after long naps.
As for how to tackle them when they happen, looks like you're doing well already? How long is he awake for before resettling? If it is OT then tweaking the routine should help, just let us know when BT is and we can put heads together.
With long naps, most people would advise capping them at 2h unless they're only having one nap, however some don't notice any ill effects from longer ones. I would be inclined not to let him have a long 1st nap though, as early/long first naps can be a cause of EWs... does he have a tendency towards those? Then again that's a bit late to say now! What was his first A time today?