Does ESP32 (ESP-IDF/Arduino/mbed-tls) support secp384r1 certificates?

Yes, I verified that mbed-tls(which is used in the esp-idf framework, which is in turn used by Arduino/PlatformIO) works fine when using a secp384r1-keyed Let’s encrypt TLS server certificate.

The version used in arduino-esp32 v2.0.5 with PlatformIO 6.1.5.