What happens on the days where his nap around 2pm is only 30mins. I would typically try to put him down at around 4/4:15 for a cn and then slee at 7/7:30 depending on how he is doing.
I would do close to a full A time (so perhaps 2hrs instead of 2hr 15) and then the nap, but you can probably let him nap a bit longer if he will/wants, especially if that second nap starts at more like 1.30pm rather than 2pm. EG:
S 1.30 - 2.00 (CN)
A 2hr
S 4 - 5.30 (full long nap)
A 2hr
BT 7.30
or with 2pm nap eg:
S 2.00 - 2.30 (CN)
A 2hr
S 4.30 - 5.30 (cap)
A 2 hr
BT 7.30
if of course that third nap is also short, well he might be grouchy and you might have to wing it but maybe:
S 1.30 - 2.00
A 2
S 4 - 4.30
A 2hr
BT 6.30
I would cut out or cut down most of the evening activity and just focus feeding and aiming for that BT because for me if somethign like this happened I'd be trying to resettle that third nap for some time and when you finally give up an hour could have passed which means that although the A time is officially 2hrs you are left with just 1 hr to get everything done such as feed, bath/wash, pjs and nappy, teeth, feed again and wind down for bed. it's a lot to fit into a short time so I'd have my fully focused head on to avoid a late BT and OT.
I hope that helps, it doesn't cover all the possibilities of course. Sometimes you just have to do what you can do.