sudo lsof -i -P | grep LISTEN | grep :$PORT those two ports, plus the expected 1815 for HMR, are the only new ports listed. plasmo dev --serve-host=localhost --serve-port-1012 to my package.json scripts (or another port like 8080) appears to have no effect. I still see 1815, 1816 and 6XXXX. For example, I have "dev": "plasmo dev --serve-host=localhost --serve-port-1012", in my package.json and just ran pnpm dev and the ports are 1815m 1816 and 64191