According to an official Adafruit learn guide, the recommended default baud rate for CircuitPython devices is 115200, not 9600 as currently used by SimplySerial. Lots of other devices (at least the ones I interface with) use 9600 as the default, however, so I think SimplySerial should switch to 115200 baud for known CircuitPython devices, and stick with 9600 for unknown devices.
According to an official Adafruit learn guide, the recommended default baud rate for CircuitPython devices is 115200, not 9600 as currently used by SimplySerial. Lots of other devices (at least the ones I interface with) use 9600 as the default, however, so I think SimplySerial should switch to 115200 baud for known CircuitPython devices, and stick with 9600 for unknown devices.