How do I stop frame drops in Onimusha 2 on Sapphire RX 9070 XT?

I was losing my mind in the Sengoku Dynasty dungeon; my character's dodges felt sluggish while frame times spiked from 8.2ms to 12.5ms. I tried locking the VRAM frequency manually, but it just made the system response even slower and more erratic. Finally, I enabled the GamePP Memory Controller Load Monitor, set the game process VRAM priority to the highest level, and disabled background sync services. The result was a massive relief: VRAM read/write latency converged to a stable 12-15ns per HWiNFO, and the temperature held steady at 65-68℃ via AIDA64.