We haven't used that technique in the case of our Islamabad office. We find that, although technology works well in some locations in the world, it doesn't work well equally. We've just found it more effective to conduct interviews in person.
As I mentioned, we send officers four to five times a year, depending on the number of cases that we feel we wish to call to interview. There's no quota. There's no magic number. It's all based on a case-by-case assessment and the complexities that we find in the caseload.
Sometimes, too, there are sensitive things that need to be discussed, and for the client's benefit, we appreciate that they'd prefer to have these conversations in person rather than remotely.