Abstract: The CMS Experiment at the CERN LHC was designed primarily to search for the Higgs boson and exotic particles with masses of a TeV or more, whose discovery would revolutionize the field of particle physics. But the LHC also provides an ideal environment for studying the exact opposite regime: well-known light mesons like the eta and eta’, with masses of less than a GeV. Despite being studied for several decades and having theoretical predictions for all of their branching fractions (BFs), many of these BFs have yet to be measured in experiment. In this talk, I will discuss the work done at CMS to measure the BF of the eta meson decay to a muon pair and an electron pair, along with prospects for similar measurements that could be performed by CMS in the future. These studies of light mesons are made possible by CMS's non-standard trigger programs, dubbed data scouting and data parking, which allow the storage and processing of orders of magnitude more data in phase spaces that are not the primary target of the experiment. Data scouting and data parking are poised to play an even bigger role in the High-Luminosity LHC era.