My ds is a well seasoned traveller too, i'd recommend
feed on schedule (as much as possible), but if asleep don't wake
try and get them to sleep as much as possible...
don't worry about ap!
Feed them on take off and landing too.
Ethan would get really tired and cry lots once we got there due to ot... we let him sleep loads the first day and started our usual schedule the second day.
You'll be exhauted too so drink loads of water and nap when the baby naps.
I'd recommend taking a baby carrier and a rucksack with baby bits. as well as a pushchair. We travelled Ba and they take your pushchair off you at the gate and you don't get it back until your luggage comes out! Hence a baby carrier is useful. Some babies go through lots of nappies as the air pressure affects their stomachs... e was ok but take enough just in case. Try to travel as light as possible.
Book a bassinet for the baby and take a blanket as the plane may get a bit chilly
Hope you have a lovely trip, like others have said just roll with it - 6hrs isn't too long, it should go quite quick x