The ECPL dynamics highlight the presence of two distinct yet critical processes in the polariton dynamics. First, the exciton reservoir is continuously feeding both the lower polariton state and the PL2 state over its lifetime of over 50 ps. Hence, the reservoir that relaxes through the PL2 pathway doesn't participate in the radiative pumping process and leaks out of the microcavity, preventing an effective population of the LP state above the condensation threshold within the polariton lifetime. Second, additional nonlinearities can be observed within the lower polariton state, that manifest in sub 200 femtosecond timescales, much faster than the time resolution of the current experiment. We have identified nonlinear scattering of polaritons close to �𝑘𝑘 ∥ ���⃗ � = 0 within the first 100 fs in our recent report . The larger nonlinearity observed for the lower polariton in comparison with the excitonic leakage not only supports our earlier observation but also strengths that this nonlinear scattering is detrimental to the population in the LP state. This further adds another critical factor that must be surmounted to facilitate the accumulation of sufficient population in the LP state for condensation. The complex emission line-shape of 2D perovskites poses a significant challenge for achieving efficient radiative pumping and polariton condensation in these systems. To reach polariton condensation, a critical density of polaritons must accumulate in the system's lowest energy state, which demands high-fluence, non-resonant pumping . However, the fluence-dependent behavior of the exciton reservoir emission introduces additional radiative recombination pathways that deplete the exciton reservoir and limit the available population to feed the lower polariton branch.