Basic vault prototype using OP_CAT

The transaction structure involved in sending funds to a vault for the first time plays a crucial role, particularly in how it differs from traditional transactions made through conventional wallets. Traditional wallets often rearrange outputs in a transaction. When such wallets are used for sending funds to a vault, there's a possibility that the output intended for the vault is placed at index 1 while the change output is positioned at index 0. This specific arrangement can lead to potential misuse in the 'complete withdrawal' scenario of a covenant case. In such instances, although the vault address is designated as the destination for the withdrawal, the amount withdrawn could mistakenly be the "change" from the initial "envault" transaction rather than the intended amount. Consequently, the unintended portion of the funds may either be allocated as change or be consumed as transaction fees. This highlights the importance of understanding and carefully managing the structure of transactions, especially in contexts involving specialized mechanisms like vaults, to prevent unintended outcomes or vulnerabilities.