I haven't done a DAFNE course, but I do see what you mean, Spiker. Personally, I wouldn't have that many snacks, but I must admit I don't want to bolus for just one finger of KitKat in mid morning - it's not needle phobia, but more that my basal insulin can deal with it until the next meal. However, I would bolus if I had all four fingers in one go! Again, it's my personal experience with the Expert meter, but if I put in 20g carbs at tea time and my bg is less than 6.8, the meter will suggest just one unit of QA, so I get a 'free' 10g carbs anyway. If the bg is above 6.8, then the meter says two units. It would be different for someone on a different ratio though; I'm on 1unit for 10g carbs, which hasn't changed since diagnosis.
I agree the advice of 'no bolus for up to 10g carbs' is rather simplistic, but I think when I was told this, there was an assumption that a snack would only be taken, say, mid morning and/or mid afternoon. To be honest, since carb counting and matching QA to the amount I'm eating, I've found snacks aren't strictly necessary anyway!
Coming to T1 rather late in the day (I'm 58), I'm grateful that the Expert meter does the calculations that many people had to do themselves; I have nothing but admiration for anyone who had to do that, or indeed still does.