the Maggio system is not a fixed set of rules. The problem with any of these embouchure methods is that they can only describe a couple of use cases. The teacher that REALLY understands the GOAL can apply that to a specific, unique person and their individual face geometry. What we learn is actually a path to development that accompanies us for the rest of our lives, not some theoretical state after finishing the last exercize.

Any embouchure change becomes the sum of what you have learned up until now. When you go at this with a DIY approach, what you "think" is important is what you get. Very often that has nothing to do with the original intentions of the author. The lower lip rolling out is not good with any method. There is really no mechanism to roll it back in while playing. I use lip slurs to build strength so that the lower lip never gets out of control. I do not use Maggio though.

I personally believe that buying a book and tackling it by yourself does NOT give you that "embouchure". It only gives you what you THINK the author meant. If the book makes you practice more and pay more attention, then it is at least money not wasted.