Nice work, Ian. Carbs have always seemed like of bit of a black art to me but videos like this on shine light into the dark corners. From what I could tell by watching, sometimes adjusting one carb affects one or more others. I suppose that's what makes it fiddly.
Would be nice to get a bit more info for people wanting to try this themselves, such as procedure involved, what connects where, what is being adjusted, what to look for etc.