Why does MX vs ATV Legends stutter in smoke on Onda A520-VH-W?

I was so excited to get high frames on a budget board, but then I noticed that entering smoke areas caused my FPS to tank from 144 to 60 per RTSS. I tried manually setting the priority in Windows Task Manager, but the settings vanished after restarting the game, which was incredibly frustrating. I used the GamePP Process Priority Manager to force the game process to Realtime and killed redundant background services. RTSS showed frame times stabilized from 11-35ms to 12-16ms, and AIDA64 confirmed CPU temps at 72-78℃. Just one switch