Thanks!
As I figured, I contacted them again and, this time, got a rep who knew what they were talking about.
Based on the response below, I'll increase the percentage at the end of the year to aim for the $17,500. By then, I will have all of the match.
Here is what they said:
...When your contributions reach $17,500 your contributions would be suspended. Please keep in mind that the sooner you reach that limit the sooner you stop receiving the 4PERCENT match. You will want to figure out which percentage will get you to the limit but take the longest amount of time so that you can maximize the company match.