ERC20Custody.sol has the following useless code in pause function which I suggest to remove. Since the function is guarded by onlyTSS the modifier, which ensure msg.sender == TSSAddress before going even further into the function, this means TSSAddress can never be address(0), which make this code totally useless. 
https://github.com/code-423n4/2023-11-zetachain/blob/main/repos/protocol-contracts/contracts/evm/ERC20Custody.sol#L122-L124
