Originally Posted by
Dave Noble
Not true
It may have used some space that might have been useable for shops, but when it existed, I used it a few times ; go through to departures and at some point before heading to aeroplane, had to go to the US pre-clearance desk and get the immigration completed.
When was this? I can't remember it ever being offered in the UK.
But I doubt it would happen again. I understand that the offer of pre-clearance overseas is done where it presents an attractive option for US CBP. The US used to have problems with Irish migration and the Republic of Ireland was excluded for some time from the visa waiver system. Presumably they didn't want to introduce a visa regime for Ireland, it would have been hugely difficult politically given the large influential Irish American population, but pre-clearance makes removals much more easier and is an expensive compromise.
The UK has a lot of third country nationals transiting Heathrow, but those that have historically caused CBP problems require visas. Until the US think that UK nationals are causing immigration problems, I don't see that they would go to the enormous expense of having lots of CBP officers working overseas, with allowances, accommodation and travel costs.
I don't see that passenger utility/experience is likely to ever be a determining factor.