Guidelines seemed to have changed between v5.2 and v6.0.2(stable); can I drive with a 3.3v external clock?:

https://docs.espressif.com/projects/esp-idf/en/stable/esp32s3/api-reference/system/system_time.html
External 32 kHz oscillator: Allows using a 32 kHz clock generated by an external circuit ...