Monitoring Daily Debit Transactions-Beneficiary

When a representative payee account is opened, we monitor daily debit transactions to make sure that the beneficiary of the funds is not signing checks. There is discussion here concerning the necessity to review these or not. We have one employee who worked at another financial institution where they did not monitor daily debit items and wonders why we do here. I am wondering if the reason to do this is that even though the account is opened under the beneficiary's name and is a single owner account the only signer is the rep payee. Also, I know that SSA's rules are that that only SSA money should be deposited to this account. There have also been discussions as to whether this is absolutely necessary or not. I guess my question is, do we need to monitor the account for signatures and if we can or should not allow the co-mingling of deposits into the account.