Proof

react-native-web-serial-api

the serial export reaches an unshimmed NativeUsbSerial turbomodule, so requestPort() and getPorts() fail; only the in-memory test transports work
0%
API coverage
No visual proof cases have been published for this package yet. The registry summary below describes what the compat layer implements.
Working (2)
only the in-memory and WebSocket test transportswhich no app uses to talk to a device
Missing
NativeUsbSerial USB discovery, device permission, physical port open and close, reads and writes, control signals, configuration, disconnect events, and Android USB transport