Environmental qualification testing of aerospace systems requires reproducing operational vibration environments under controlled laboratory conditions. For free‑flying or slender structures, conventional single‑axis tests and rigid-table multi‑axis setups can introduce significant impedance mismatches and non-representative boundary conditions, reducing the fidelity of the reproduced environment. Impedance‑Matched Multi‑Axis Testing (IMMAT) addresses these limitations by connecting actuators directly to the Device Under Test (DUT). This method helps keep the interface impedance low, approximates free-free boundary conditions more effectively, and attempts to better replicate load paths, although fully distributed loads (e.g., aerodynamic excitation) cannot be replicated exactly in a laboratory setting. Despite these advantages, IMMAT test planning still relies heavily on engineering judgement, with limited tools to quantify environment replication accuracy a priori or to verify that shaker and amplifier limits (force, voltage, current) will remain within safety margins.