Wireguard Pre-Shared key Purpose?

Installing and Using OpenWrt Network and Wireless Configuration
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BTW, you cannot change a public key without changing the private, and vice versa, meaning the method of identifying your peer changes.

Yeah, So I have figured out a couple of possibilities for rotating the Wireguard key(s),

  1. By modifying the Private & Public key pair in both peers.
  2. By rotating only the Pre-shared key in both peers.

Of these which option can go with for efficient Wireguard key rotation,