I'm not exactly sure what Mod B is like now since I did it in the old syllabus. However I got a 97 in advanced english and I used pronouns in the Mod B like my understanding. I also opposed some of the critic comments i included by giving my own opinion and specifying by saying something like 'However, in my interpretation'. Risky move on the part of the critics but I did it in a way that was justified and well written.
However in saying that just because you use personal pronouns or if you don't write them, it will have little impact on your mark. What you write is obviously your analysis and so even if you don't write my understanding it is clearly your interpretation and understanding of the text. So I wouldn't worry too much about that aspect, just do whatever you did in trials already and previous assessment tasks because you don't want to try make a change going into HSC if you don't know how to write it in that way