I was going to say, don't detour from the plan in any way now, no maintenance on rest days. Feed it like you said, if Vector can't keep up you are getting fat call it for what it is, and say did not work as well as predicted, that you are getting too fat and need to drop calories because the product did not justify the surplus.
That is kind of the point of it right? If you get to a point you have to yield the caloric increase in any way due to gaining fat too fast you have already proven the high caloric surplus is not justified or needed. If not and you are packing on more muscle than fat then you are proving it works as predicted.
However I would just take it to whatever your personal cut off point for fat gain is. No farther than that, you don't have to get fat to prove or disprove this, just to the end of your composition comfort zone and then make whatever adjustments you need to and then just tell us you had to make an adjustment and why.
In the end just call it like you see it. Hopefully that is noticeably more muscle growth than usual.
I think I disagree here at least to a point.
In any diet adjustments need to be made along the way. No intelligent diet coach would prescribe a diet and just say adhere strictly to this period and never look at it again. He would be fired and for good reason. Even with high doses of AAS I wouldnt suggest this. Everyone has seen pictures of heavily geared guys who are fat as hell. Steroids not working? No, diet coach not working.
Adjustments will almost certainly need to be made along the way.
This is a big part of the problem people have growing as bodybuilders. Lack of guidance from someone who knows what they are doing.
If you just eat as much as you can everyday aimlessly you will almost certainly get fat regardless of supplementation of any kind except for maybe t3 and clen etc.
So....keep an eye on bodyfat.
If you start getting soft make adjustments. Im not suggesting pulling calories. Im suggesting shifting them from carbs to fats and protein.
And cut off carbs earlier.
And increase cardio. Say your doing 20, go to 30.
Fat will drop off quickly as muscle continues to climb.