I think you’re missing a lot here.
First you underestimate the type of carbs. The rice oligodextrin and the isomaltulose are slow carbs with the lowest GI, which means that your insulin levels won’t rise.
Second 10min before the workout you’ll spike your insulin levels which will transport all the good stuff you’ve took before, and by opening the “doors” to the cells insulin is being used, so it will drop to some level.
Third when training your body will release more hormones (catecholamines and glucagon) which will prevent the further spiking of insulin, while insulin will still be present, but not at high level. As you know you need insulin to take advantage of the GH.
Fourth you are forgetting about the Alpha GPC which will help producing more GH after the workout.
I think this is the main idea of the protocol, CT isn’t talking about “any” carbs at “any” time. There is a lot of timing and other supplements, which you’re totally underestimating. 