The ability to predict and computationally tackle electronic excitations is key for guiding the development of new materials in many areas ranging from quantum technologies to ultrafast electronics. In this context, materials hosting strongly coupled electronic states are particularly interesting, but they pose a significant challenge to theory. Fortunately, the most important contribution is, in many cases, limited to only a small range of electronic states, i.e., a subspace of the system. Therefore, a small explicitly correlated problem (solvable computationally) can be embedded in the remaining portion of the system, which is treated at a more approximate level. However, determining the correlated subspace is not always straightforward. Further, the strongly interacting states are coupled to the rest of the system, and the extent of the dynamical coupling depends on the size of the explicitly correlated region. The importance of the dynamical renormalization has been recognized and the constrained random phase approximation (cRPA) has become a standard in accounting for the dynamics of the environment outside of the correlated subspace. For technical reasons, a static limit approximation is ubiquitously applied, and cRPA calculations are computationally prohibitive for large systems. In this work, Mariya Romanova et al from the Department of Chemistry and Biochemistry of University of California, introduced an efficient stochastic cRPA (s-cRPA) approach and described a complementary strategy in which the weakly interacting environment is downfolded on the correlated subspace and the dynamical interactions are fully taken into account. It is captured via renormalization of one and two quasiparticle interaction terms which are evaluated using many-body perturbation theory. The authors outlined the strategy on how to take the dynamical effects into account by going beyond the static limit approximation. Further, s-cRPA enables treating the host environment with a large number of electrons at a minimal computational cost. For a small explicitly correlated subspace, the dynamical effects are critical. They demonstrated the methodology by reproducing optical excitations in the negatively charged NV center defect in diamond, that agree with experimental results. This work is a jumping-off point for future practical simulations of electronic excitations in localized quantum states.