I think that is a great idea on the no carb pre-workout, then sipping the intra starting just before your warmup. I would definitely add some more carbs to your intra drink, then get in the practice of finishing off the drink immediately post workout if it is not gone already. Then go for the post workout meal. Say if you really wanted to push things on training days you could add 100 grams of carbs that is 400 calories. Just bump the intra-workout drink by 55g of carbs and add a cup of rice to your post workout meal and you are done! If you are worried about fat gain then obviously don't make that big of a jump. You are more familiar with your metabolism so you would want to decide that.
I am kind of ambivalent on the GDA prior to the workout, especially if not having carbs in the pre-workout meal. Without carbs pre-workout and using that I might be a little concerned with the possibility of going a little hypo before the carbs from the intra workout get into the system. The glut-4 translocaton (what causes exercise induced insulin sensitivity in muscle) is going to start pulling in nutrients once you start working, if the carbs don't get into the system in time blood sugar could drop temporarily causing weakness or dizzyness. Now this exercise induced increase in insulin sensitivity is only in the muscle tissue which is part of the reason the people say the best time for a lot of calories is the peri-workout window. You are far less likely to store fat when Glut4 is pulling everything it can into the muscle tissue. So I am not really sure that you need it there.
I do think that a GDA post workout or even mid workout is a good idea, I also think you want to look at your GDA and make sure it focuses more on Glut 4 increased sensitivity than overall sensitivity. In other words ones that act on the insulin receptors in the muscle but do not increase sensitivity in fat cells. Berberine is probably my favorite in that aspect but some get some softer bowels from it. I think there is another one that is a compound of fenugreek that does this well too. So I tend to look for those, but really post workout when most of the Glut4 is already activated taking something that increases overall insulin sensitivity is still going to be limited on fat gain due to the extreme thirst of the muscle tissue created by the glut 4 translocation reaction to training.
Probably deeper into that then you were asking but that's how my mind thinks.
I am kind of ambivalent on the GDA prior to the workout, especially if not having carbs in the pre-workout meal. Without carbs pre-workout and using that I might be a little concerned with the possibility of going a little hypo before the carbs from the intra workout get into the system. The glut-4 translocaton (what causes exercise induced insulin sensitivity in muscle) is going to start pulling in nutrients once you start working, if the carbs don't get into the system in time blood sugar could drop temporarily causing weakness or dizzyness. Now this exercise induced increase in insulin sensitivity is only in the muscle tissue which is part of the reason the people say the best time for a lot of calories is the peri-workout window. You are far less likely to store fat when Glut4 is pulling everything it can into the muscle tissue. So I am not really sure that you need it there.
I do think that a GDA post workout or even mid workout is a good idea, I also think you want to look at your GDA and make sure it focuses more on Glut 4 increased sensitivity than overall sensitivity. In other words ones that act on the insulin receptors in the muscle but do not increase sensitivity in fat cells. Berberine is probably my favorite in that aspect but some get some softer bowels from it. I think there is another one that is a compound of fenugreek that does this well too. So I tend to look for those, but really post workout when most of the Glut4 is already activated taking something that increases overall insulin sensitivity is still going to be limited on fat gain due to the extreme thirst of the muscle tissue created by the glut 4 translocation reaction to training.
Probably deeper into that then you were asking but that's how my mind thinks.