Doesn't that then leave the entire personal check (less $200) available for the C by C hold.
I believe it technically does, though I have never actually seen this done. The commentary does state that when a large deposit includes a mix of checks that would have different availability schedules, the bank has discretion to choose the portion of the deposit to which it applies the exception hold.
From the commentary to 229.13(b) on Large Deposits:
1. Under the large deposit exception, a depositary bank may extend the hold placed on check deposits to the extent that the amount of the aggregate deposit on any banking day exceeds $5,000. This exception applies to local and nonlocal checks, as well as to checks that otherwise would be made available on the next (or second) business day after the day of deposit under §229.10(c). Although the first $5,000 of a day's deposit is subject to the availability otherwise provided for checks, the amount in excess of $5,000 may be held for an additional period of time as provided in §229.13(h). When the large deposit exception is applied to deposits composed of a mix of checks that would otherwise be subject to differing availability schedules, the depositary bank has the discretion to choose the portion of the deposit to which it applies the exception. Deposits by cash or electronic payment are not subject to this exception for large deposits.So, to clarify. I believe you technically could hold $1,500 of the cashier's check under the large deposit exception hold (according to the commentary quoted above). The remaining $2,000 of the cashier's check would be subject to next day availability. Then, this leaves you with the $3,000 from the personal check where $200 must be made available the next day and the remaining $2,800 could be held to second day availability. In other words, $2,200 available next day, $2,800 available 2nd day, and $1,500 available 7th day.
That said, while this may be technically permitted under Regulation CC, I see this as too complex to attempt to allow staff to use regularly. In addition, how much benefit is there in delaying the additional $2,800 by just one more day?