Yes you can!
You can set a Maximum Daily Save limit per individual goal that you're saving towards in Digit. This will keep Digit from saving more than the amount you specify for that particular goal in each day's savings calculation.
To set this:
1) Open the app
2) Tap into the goal you'd like to set a limit for
3) Tap 'Settings' in the upper-righthand corner
4) Select "Maximum Daily Save Amount"
5) Enter the desired amount you do not want Digit to surpass when saving towards that goal and click "Save"
To remove your currently set Maximum Daily Save amount:
Repeat steps 1 through 4, you will see an option to now turn this amount off.