Recent EV inverter power modules continue to push toward higher power density and tighter integration, making junction-temperature control a primary design constraint that directly governs functional safety, lifetime, and overall drivetrain efficiency. Direct jet-impingement cooling has emerged as a promising thermal-management strategy. It forms an extremely thin thermal boundary layer at the stagnation region, delivers heat transfer coefficients far exceeding those of conventional horizontal-flow cold plates, and readily enables TIM-free direct cooling while maintaining sealing practicality. In practical EV systems, however, multiple modules are connected in parallel, and the crossflow generated in the outflow cavity perturbs the impinging jets. This degrades local heat transfer, induces temperature non-uniformity among modules, and raises pumping-power consumption. In this study, we propose a jet-impingement flow-path design that incorporates a central collecting manifold, and we aim to clarify how this architecture suppresses crossflow-induced degradation and excessive hydraulic losses while minimizing module-to-module performance variation in multi-module configurations. We seek to understand how the key geometric features governing jet characteristics affect cooling capability and energy efficiency, and how the proposed design compares with a conventional flow path without a manifold. We further examine how much surface modification and double-sided cooling can improve efficiency at the packaging and system levels, respectively, in order to assess each approach's contribution to high-efficiency cooling for EV-grade inverter modules.