Molded articles are provided. An exemplary molded article includes an inner panel portion, a main body portion, and a contoured portion extending between and interconnecting the inner panel portion and the main body portion so as to surround the inner panel portion and be surrounded by the main body portion. The contoured portion includes contoured corner segments and contoured elongated segments extending between respective pairs of the contoured corner segments. The contoured corner segments have a first maximum thickness. The contoured elongated segments have a second maximum thickness that is greater than the first maximum thickness. Related methods, assemblies, and apparatus are also provided.