A preprint posted to arXiv (https://arxiv.org/abs/2603.24778) establishes a unified framework for quantum mode parameter estimation, the process of measuring properties like time delays or frequency shifts in electromagnetic waves that power radar, lidar, and optical clocks. This purely theoretical work, which has not yet been peer-reviewed, uses mathematical analysis to identify the key physical resources (such as mean frequency and bandwidth for time shifts) tied to the eigenmode basis of the transformation. It derives a tight upper bound on the quantum Fisher information for multimode Gaussian states, analytically identifies the optimal states that saturate the bound, and shows that multimode homodyne detection is the optimal measurement. As a non-experimental study, it involves no sample size or empirical methodology; limitations include its restriction to Gaussian states and specific mode transformations.