I don't know that the dietary strategy laid out for you is the best way to go forward. I am not saying it isn't. However to me personally it sounds like a recipe for digestive issues, increased inflammation, and discomfort. I am not saying it is not an effective way. It has been proven over and over that the restrictive bro way of eating gets the job done. However it also has a lot of known drawbacks and unnecessary discomfort and restrictions. It is like the Bro Based Elimination diet for Body Building, except it contains almost everything that is typically removed in an elimination diet due to being very inflammatory.
Nutrition is really very basic with a few tweaks but most of it is over thought. When it comes to composition most of it is energy balance, then comes macro intake based on insulin sensitivity, which also brings timing into the picture. Here are things I think you need to consider for your goals here.
Energy Balance is about 90% of it - you need a surplus for gains, and a deficit for losses
Carb tolerance / Insulin sensitivity - carbs you need specificity of use, type and timing. Taking them in moderate amounts throughout the day is doing nothing to improve insulin sensitivity, just trying to maintain status quo... Lowering carb intake outside of the peri-workout window and increasing carb volume as high as comfortably possible during the peri-workut window will be more successful in managing insulin sensitivity and also allow you more freedom. Keeping sugar down isn't the answer. You actually want about 30% of your post workout carbs to be sugar and fructose as it greatly increases insulin sensitivity following training. More so than just quick digesting complex carbs for certain. Has been proven. If you want 200-600g of carbs a day that is easy in the peri workout window and the meal following it if having mixed sources of carbs. You find your tolerable carb level while maximizing insulin sensitivity and then fill the rest of the caloric needs with adequate protein intake and fats.
I see no need to go anywhere near 400g of protein, I get that he is thinking of TEF and positive nitrogen balance but that is a lot of protein making digestion harder than it needs to be and eating up to 7-8 meals a day to be able to eat all of these hard to digest carb sources as well as 400g of protein is just inconvenient with no benefit over fewer and more enjoyable meals with the same caloric intake but more easily digested foods that in many cases have better micronutrient profiles.
The real important stuff is more about health, provides micronutrients, ease of digestion, if it causes inflammation, is it enjoyable, is it maintainable, is it convenient, all of these things are literally more important than any of the composition specific benefits of eating the bro way, which incidentally will not provide better benefits outside of increased TEF from the high protein but that benefit is negated by the stress it puts on the additional stress it puts digestive system in my opinion. Same with all the whole grain recommendations.
Personally, I would put all of those things in consideration over just following that advice. Again I am not saying it isn't an effective strategy, to argue that would be ridiculous, I just think there is a better way that will be more comfortable without causing any more fat gain than what was being suggested and in my opinion likely to be less fat gained while improving digestion, absorption, insulin sensitivity and metabolic flexibility.