It is difficult to measure and correlate power delivery network (PDN) for Mixed Reality (MR) Systems with Rigid Flex printed circuit (RFPC) designs using conventional techniques. This is due to high density routing and the small form factor. Traditional hybrid EM simulators are used to model PDNs for rigid single stackup PCBs, however these solvers run into limitations when working on multi-zone (MZ) or multi-stackup rigid flex designs. Moreover, accurate dynamic chip current simulation capability is lacking, which leads to errors in on-chip PDN droop correlation. This paper investigates various simulation best practices and measurement methods to achieve good correlation for power delivery of Mixed Reality Systems. Overall, this paper provides a valuable contribution to defining a PDN correlation flow of multi-zone RFPCs used in mixed reality design and has implications for the design of future MR systems.