I took time off for personal reasons and to take licensing exams for the UK. Ran into some logistics problems and ended up wasting more time than I should have.

I’d suggest to consider long term career goals and motivation. Most physicians I know who did their MPH or MBA did it after finishing their residency. As someone who has taken time off after medical school I can say it is difficult to go back to clinical medicine unless you are really motivated or passionate. Getting it done before graduation has the benefit of not slacking off later in your career or losing the motivation. If you are in the routine of studying, my recommendation will be to go for your MBA/MPH and get it done. That way 4th year will help serve as a smoother transition period in my opinion.