We develop new analytic descriptions for solitary waves (SWs) and SW-like objects in the non-integrable and strongly nonlinear β-Fermi-Pasta-Ulam-Tsingou (β-FPUT) system for various strengths of the harmonic term in the potential. We then show that that the collision of identical solitary waves in the decorated β-FPUT chain can lead to the formation of one or more long-lived localized nonlinear excitations (LNEs), thereby suggesting that these systems allow engineering of preferential energy distribution over extended times. © CopyrightEPLA, 2018.