Something that is easy to forget is that when some activity is assessed by government or some public body, that the organisation or people being assessed will inevitably hold at least one mock/pilot exercise, which is at least as onerous than the real one (perhaps more, as the feedback is often more thorough). I’ve seen examples of this in public examinations (when head teachers complain about the “constant” exam load on their students, it is worth bearing in mind that students are doing one mock exam for every real exam) and in universities with research assessments, teaching inspections, etc. I’m sure the same is true for hygiene inspections in cafés etc., and with quality assessments in hospitals, prisons etc.
Therefore it is worth bearing in mind a rule of thumb: if you say “X will happen every (say) four years”, on the ground it will seem like it is happening every two.