Here in the States, the proximal is the default, and there are specific standards of care that are defined within the insurance billing codes; the distal is outside of that standard and is not usually approved as an initial surgery, but can be justified as a revision if deemed appropriate. Here, for the higher BMI cases that need something stronger than a VSG or proximal RNY, the duodenal switch is the normally approved procedure.
My wife's surgeon noted at one time that on the occasions that he still did a bypass (their preferred is the duodenal switch) that he liked to make them as malabsorptive as the codes permitted, which is still far short of what a distal would provide.