We used to stop all the time in Anchorage for our flights from Asia to Canada for crew changes and fuel while trying to do a quick turn around but not anymore if we can help it.
US Customs at Anchorage is one of the worse stations I have ever dealt with especially is you want to accomplish a quick turn.
Often they will want every passengers to go into their terminal for complete customs procedure including all their luggage. Why can they not, like at a lot of other airports, just clear the people onboard? They know the pax are not getting off in Anchorage and that they were most likely sleeping on these flights.
Then they will even throw away all your catering so new catering must be ordered in Anchorage for the flight outbound.
Don't they understand what a "tech stop" is? All we want is fuel and a crew change, nothing except the crew getting off the aircraft needs to clear US Customs.
We now go directly weather and airport permitting directly to a Canadian port of entry.