Ok so I have another question regarding this book and it’s semi more intelligent than the last one😂.
But the necromantic masters and their sigils given, it talks about a specific evocation method that proves to be better then ordinary traditional methods. So my question is could one as well perform other forms of contact/opening the sigils ect. I’m asking cause I noticed on the evocation there is stuff you say and such.
How is it “better”? Do they show up in a tuxedo with a bouquet of flowers and a bottle of wine? Do tell! 
I’m sold! I’m kidding obviously, but really if you can evoke you can evoke, no? Did you try it and find it’s different, faster, clearer or something?
I would say no, if you’re using a given book, it’s for a reason and you want to follow it as well as possible, to give it a fair chance if nothing else. You can start switching it up once you get a feel for it to get a comparison.
Otherwise don’t say you’re using that book, make up your own ritual that’s “inspired by” the book, but know it’s not the same thing and results can’t fully be compared with others following the actual method in the book.
I’ll definitely follow the book I was just curious since the book didn’t specifically say(or at least I didn’t see it) that you can ONLY use that method so I was just curious
One can use any evocation method or formula, however the method spoken off merely resonates with the system in such a way that due to the prepatory immersion, the preliminary processes and such, create a unique synergy with this method the necromancer can use the sudden changes in accordance with this method. Adapting sometimes to the working system or tradition can produce more tangible results. These are sometimes as simple as easier ritual format, less drain on your energy, quicker or more solidified presences etc.
The main thing I like to do with my written works is simply give a recommended formula, however it’s merely a blueprint it can be adapted in accordance to how you wish. There are only small instances and things which I recommended one does not change. Such as the idol, the urn, and such as these vortices are unique and it was specified to me by the spirits themselves to use minimal but specific implements.