Clinical perspective, offered as context rather than as advice. Order of operations matters more than any single choice here: establish a baseline, change one thing, wait long enough for it to express itself, then measure again under the same conditions.

From the other side of the consultation, briefly. The useful move here is to separate what is established from what is widely repeated. Those two sets overlap less than the confident tone of most write-ups suggests, and the second set is where nearly all the disagreement on this board comes from.