When two SRM chromatgrams contain almost the exact same values for precursor/product m/z pair (i.e., too close to be distinguished using the existing Q1/Q3 accuracy), then the chromatogram returned for either pair would always be the one whose first RT observation was earlier. This was because, the filterline of the first scan found to match the queried precursor/product pair was imposed on all subsequent observations for the chromatogram (of that query). This has been fixed by constructing chromatograms for all pairs in the given range and then selecting the best among them.
When two SRM chromatgrams contain almost the exact same values for precursor/product m/z pair (i.e., too close to be distinguished using the existing Q1/Q3 accuracy), then the chromatogram returned for either pair would always be the one whose first RT observation was earlier. This was because, the filterline of the first scan found to match the queried precursor/product pair was imposed on all subsequent observations for the chromatogram (of that query). This has been fixed by constructing chromatograms for all pairs in the given range and then selecting the best among them.