In recent years, there has been a growing interest in using polygonal elements to solve differential equations numerically. These elements offer the same flexibility in grid generation as triangular elements, as well as enabling rapid image-based meshing using the quadtree algorithm. One method of constructing higher-order basis functions for these elements is based on the semi-analytical Scaled Boundary Finite Element Method (SBFEM). However, for dynamic simulations of the linear elastic wave equation, an efficient time step method is just as important as efficient meshing. Mass lumping is a popular method for reducing computation time in explicit time-step methods. In the authors' opinion, the available research on mass lumping in combination with the SBFEM is incomplete, particularly with regard to the higher-order bubble functions of Ooi et al. [1]. It should be noted that this differs from the bubble function of Gravenkamp et al., which has already been investigated in relation to mass lumping [2]. In this contribution, we examine the use of explicit time-stepping combined with the SBFEM to approximate the 2D linear elastic wave equation on polygonal meshes, incorporating a mass‑lumping strategy to accelerate simulations. We detail the modifications required in the formulation presented in reference [1] to enable effective mass lumping and demonstrate through numerical examples that this approximation does not compromise accuracy when using linear and quadratic shape functions [3]. The use of mass lumping significantly reduces computational time, thereby increasing efficiency. Furthermore, the proposed simulation framework retains the meshing advantages of the SBFEM. We present results for polygonal meshes derived from both CAD-based triangular meshes and image-based quadtree meshes. For the first time, we present results on the extension to cubic shape functions for quadtree grids.