<p>The evolution of propagating and standing waves in a one-dimensional elastic lattice of 3D massive potential wells with light particles inside is analyzed. The potential wells/containers represent soft-walled 3D versions of chaotic billiards coupled with elastic springs as a one-dimensional lattice. The proposed shape function allows for a switch from the repelling to the stadium type of container walls by varying the shape parameter. The results reveal how the geometry of containers affects the intensity and irreversibility of energy flows from the chain of containers into the ensemble of their light inclusions. Typically, cells with repelling boundaries generate a stronger chaotization of the inclusion dynamics with irreversible trends of energy accumulation from the ensemble of containers until certain thermodynamical equilibrium is reached. As a result, propagating waves are destroyed by giving rise to standing or slowly drifting waves of chaotic mode shapes with decaying amplitudes.</p>