The ERC721 token, closely related to ERC1155, has a _safeMint mechanism, where a contract recipient must implement onERC721Received to receive the minted NFT, otherwise, the call will revert. This is to ensure that contract NFTs cannot be stuck in smart contracts.
However, in OpenZeppelins ERC1155, the function _mintBatch() requires that a contract user must be able to accept the token, that is, it implements the ERC721-like safe mint mechanism by default.
This brings forth an edge case where contract recipients (e.g. multisigs) may fail to delegate due to not being able to accept the token. We urge the sponsor to double check on whether this is the intended mechanism.
