to be clear, there is no protocol interaction between the nodes to rotate keys or update the polynomial. you simply use your nsec to generate a new set of shares, then swap out the shares manually
this keeps share rotation simple, and reduces the attack surface available to a compromised share
I do have an example of performing an interactive rotation in the main frost library, that is designed for a group of adversaries:

GitHub
frost/test/example/refresh.ts at master · cmdruid/frost
Flexible, round-optimized threshold signature library for BIP340 taproot. - cmdruid/frost