After submitting an ATIP request Mar 2022 for GCMS notes with zero response, I submitted letters to my MP and my conclusion is that the best thing to do is submit another ATIP request after six months and in the box where you describe what you are asking for, include your timeline events (you don't have much space) or attach a document outlining your timeline. I submitted two more ATIP requests after not hearing from the Mar 2022 request, and I provided the timeline and indicated how many YEARS it had been, and within 2 weeks there was a request for biometrics. Within 2 hours of the biometrics being submitted, there was an ADR for updated forms. I assume they can't make a decision with the original documents as they are too old.