I can't contribute much in the way of GT fishing experience but living in the UAE I have transported rods / sections many times from the UK.
I wouldn't use anything but a piece of upvc drain / fall pipe after Emirates managed to pretty much fold in half what I considered to be a VERY robust cardboard tube
No need for end caps, I make sure the tube is bit longer than the rod at each end and pack it with bubblewrap or even crumpled up newspaper to cushion the ends. Cut out a circle of corrugated card for each end and then use multiple layers of parcel tape to seal the ends.
Write fragile on the tube a few times and cross your fingers.................
Just joking, I've never had a problem after parcelling up a rod like this and it costs vey little compared to the price of a decent rod.