Great question! Absolutely, there are two ways you can limit your monthly Overflow.
You'll be sent an email reminder on your balance check date (by default, it's the 18th of every month). That email will give you the option to skip that month's deposit, if you want to keep more cash on-hand.
You can also add a maximum to your monthly Overflow. Let's say you have $25,000 and the account balance you've set is $10,000. This puts you at $15,000 Overflow deposit. You can set a $5,000 maximum per month, so when we automatically move your cash, we'll only move a maximum of $5,000, even if you have more than that in excess.