Best practices/questions about using esp_now with ESP32s

[Imstarboard]

Can anyone answer these questions about getting multiple esp32s to communicate directly using esp_now:

- In order to get 2 ESP32s to communicate back and forth, does each ESP32 need to establish a session (esp_now_add_peer) with the other (A calls with B AND ALSO B calls with A), or if only one needs to make the call, how would the other transmit to the initiating ESP32?

- What is the best practice around testing to make sure a session is still active and re-initiating if the session is no longer valid - is there any harm in re-connecting a session if the session is still established (in case one of the ESP32s got rebooted instead of simply failing to respond to one transmission)?

Thanks!