Recent studies in optical metrology of laser powder bed fusion (LPBF) indicate that there remains insufficient understanding of the optical phenomena that occur during laser-matter interaction, which limits the accuracy of non-contact measurements for multiphysics model validation applications. The primary causes of measurement inaccuracy appear to be related to the interaction of process byproducts (including metal vapor, condensate, and ejecta) with light propagating to and from the melt pool. To better understand, quantify, and mitigate the deleterious effects of LPBF byproducts on the melting process and optical measurements thereof, a highly configurable benchtop setup is under development in conjunction with the NIST Additive Manufacturing Metrology Testbed. The new experimental setup additionally aims to advance research in laser coupling, laser spot size metrology, and the effects of shield gas flow distributions. This presentation outlines the known challenges and opportunities while inviting feedback from the modeling community.