During the course of this work and the preceding years of P&D operation, the team has encountered a range of technical challenges most of which we have alluded to above. In this regard, while most stand-alone probe sources are designed with the needs of their users in mind, it is important for scientists to be able to navigate across multiple sources to get an overview of all potential probes in advance of experimental planning. This presents a particular challenge for non-informaticians and for which we needed much data-wrangling effort to complete the overview that P&D now offers.