I forgot to answer this part.
Which library do you use?
I don't use any library, I write all of my own code from scratch, usually in assembly language.
The libraries of Mario H. and DFRobot don't provide the ablitiy to provide specific IO pins for the outputs.
I don't know anything about those libraries and since you didn't include a link, and since I have obviously never heard of Google, I gave you an example based upon a library that I am familiar with.
This is the declaration of the .begin statement.
The .begin statement gives the library information about the characteristics of the display but does not give it information about the interconnections between the display and the Arduino.
Don