My MS-Challenger B850M-K keeps dropping CPU clocks during fast building in Fortnite, how do I fix this?

Whenever I was building fast, I noticed these tiny, annoying frame skips that were incredibly obvious at 2K resolution. The VRM module on the Maxsun MS-Challenger B850M-K just couldn't handle the transient power peaks, with voltage swinging by 0.15V, which triggered a slight CPU downclock and caused frame time jitter between 10-25ms. I first tried the High Performance power plan in Windows, but that was a joke—peak clocks went up, but my 1% lows actually dropped by 8 FPS. I realized this was a physical cooling issue, so I rigged up a small fan to blow directly onto the VRMs and manually capped the CPU power limit (PL1/PL2) to 95W in the BIOS. Monitoring with RTSS showed the frame time variance shrink from 12-40ms down to a tight 8-14ms. The building experience is finally snappy. Interestingly, the PC rebooted twice under low load right after the cap, until I switched the load line to medium mode. VRM temps now sit at 72-78℃ and CPU at 65-71℃, with memory staying between 58-63℃ after a 3-hour stress test.