Why does Nightingale FPS drop when building structures?

While building magical structures, I found the i9-13900K load bizarre: E-Cores were maxed while P-Cores sat idle. I first tried disabling all E-Cores in BIOS; while it fixed scheduling, multi-core performance plummeted and overall FPS actually dropped. I then enabled GamePP Process Priority Manager to force the main thread onto P-Cores and set the Ultimate Performance plan. Cinebench R23 scores rose to 37800 points, temps hit 75-82℃ per HWMonitor, and FPS stabilized at 110 via RTSS. Finally, the power is unleashed!