Along the way we've been offered ways to get around this and that which we've politely declined. Most obvious one being put your HQ in some country you've never been to in your life, we'd save buckets.

Also, if you get down to the metal with VAT there's a lot of ambiguity (opportunity).

My experience is that scale is not a prerequisite for it being economically beneficial.

Pretty much. Only once a companies' net income reaches a certain level does it start to become beneficial to play the international tax game.