Can't imagine you need a gda on cycle during a cut, makes no sense. Would maybe help in pct.
Considering the compounds he is using yeah a GDA would be beneficial. He is not getting the high amounts of IGF in his muscle off of such weak pro-hormones that others do running a strong DS. I mean it isn't like he ran DMZ or Tren, even at high doses the products he is using simply are not going to provide that same kick.
On top of that most people misuse GDA's anyway. You use them when you are NOT taking in a ton of carbs to get a GLUT-4 response that is equal to a large insulin spike but from minimal carbs. Unless on a serious bulk where fat gain is not a concern GDA's should be used at times when you wan't the effects of an insulin spike without an actual spike or ton of carbs. It is about being able to shuttle as much nutrients in the muscle as possible without having to overfeed yourself to get the response.
When you use a GDA with a low-moderate carb intake you still get the shuttling effect like if you had a massive quantity of carbs. The muscle soaks up the available nutrients from the low-moderate carb meal before the glycogen stores fill completely so none of the carbs get stored as fat. However if you take a GDA to increase insulin sensitivity then have a fug load of carbs you have increased insulin sensitivity not only in the muscle but also the fat. Since a plethora of glycogen available and tons of insulin you have set yourself up to be more likely to store fat. Hence why GDA's should only be used during cuts, or recomps, but typically not for a bulk unless fat gain is not a concern.
I definitely agree that GDA's are beneficial in PCT, and typically not needed on a cycle. However the compounds he is using are not going to cause the major increase in IGF-1 that stronger designer steroids do. Admittedly IGF-1 is definitely a far greater GDA than any we mentioned before. Shoot it can easily make you go hypo.