Can I change scaling parameters or wrong/right in the text file and this will have an effect in 'Marking'?

Yes.

Do I have to do 'Update documents'?

No.

With Update marking scale on, the marking process begins with txt->tex conversion, then uses the latex engine to process the tex file and extract the marking strategy, before computing the marks.

Update documents will rebuild the question, correction, and erease the layout data (it must be rebuilt then). This is dangerous to call it after the exma took place, because if the source file was modified, this could make different subjects, so that the scans won't be recognized... (there is a warning to tell you you're going to make a mistake).

In the sequence of previous posts I want to "Update marking scale on" but how to change scores?

Exam sheet uses LaTeX as seen in the link

http://home.gna.org/auto-qcm/auto-multiple-choice.en/latex.shtml

but I cannot find in the tutorial how to change scores in questions like:

\begin{question}{Cap1}
    Some text:
    \begin{choices}
      \correctchoice{this is correct}
      \wrongchoice{this is wrong 1}
      \wrongchoice{this is wrong 2}
      \wrongchoice{this is wrong 3}
    \end{choices}
  \end{question}

Thanks,
Pedro

(Own) answer in:

http://download.gna.org/auto-qcm/auto-multiple-choice.en.pdf

"Auto Multiple Choice"
Design of MCQ tests with automated correction and grading
(http://home.gna.org/auto-qcm/)

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