You are right that 30min naps are often OT but some kiddos will do UT ones lasting 30min. So yes I would push the A gently. how long is the second nap? After 1.5h A and 30min nap?
Re feeding some of Tracy's advice is outdated now and we believe if she lived she would update it. One point is that some ebf kids don't manage to go to 4h between feeds. Mine could but I was cluster feeding until 5/6mo when I introduced bottle and solids. So you may try feeding him twice during A time, either shortly after first feed or just 30mkn before sleep. You also may keep 4h if that suits him, but feed him around 3, 5 and 7pm - that's what I did.