Is the exit limit for each wake up or all night?
Let's say that you've set a limit of 3 exits and your child uses all 3 exist at bedtime. Is that it for the whole night or should you start the exit count back at zero for a middle of the night wake up?
It's really up to you.
You may want to start out allowing 3 exists for each wake up and see how they do. But if things aren't improving, you can change it to 3 exits total for the entire night.
The lower the limit for the entire night, the faster the process will be.