I have been Googling this question from @Jon-Manchester and came across this thread, and I find Paul's answer interesting/concerning....depending on how you read this, but I have been using these 'drops' as an indicator for my extended bolus cals. Do I'm using an OmniPod Dash system, and I have always used these blood indicators in the same way that @EmmaL76 had mentioned, so the higher the blood drop count, the more bolus I deliver immediately, against how much I leave extended and for how long.So I have been thinking about this and I think I have worked out the logic. They are using the 5g carb as a generic ICR and therefore if the food is listed as 35g Carb and they put 7 blood drops up then this means you will need 7 units of insulin for that particular part of your meal. So you would go through the whole meal you are about to eat and add up all the blood drops and that would be how much insulin you need to cover that meal.
It's been working for me, but that might just be a happy accident.