`````boxes pallets and containers along with documents couldn't give stuff where they depart/arrive .
Much of the hardware exports/import could and do travel through regional airports (mainly the MAG group !) and via road /rail to the lowlands every day.
Under floor use useful but not the be all and end al!
And as a vehicle in the LHR needs a 3rd runway because its a rather weak argument on its own!
And the China route queue is a myth right now - The UK is not welcoming to the Peoples Republic with all the Visa issues combined with the rhetoric over immigrants conflated with asylum seekers currently.
As for Brasil its remains a tiny market for the UK in every respect other the timber and thats put on ships to you guessed it the lowlands put on smaller ships and landed in places such as Hove !
India is a basket case low profit VFR and even lower profit (for UK PLC) transit traffic to/from the US
The other bric -Russia well the UK are having our own little cold war right now.
Other than Oligarchs hiding their money and flying rather luxuriously in/out of Luton - The market has collapsed !