The other option is to install clay for your batters box. We just redid our infield playing surface for our fields last August to a "synthetic" dirt. We took out the jox boxes that were installed on the fields and installed clay because the jox box wasn't necessary with the new mix and they weren't 100% sure it would work with the mix. We only played one season on the new fields with the new batter's box, but we have had no issues. Many players say they absolutely love them because it is close to impossible to "dig in", which keeps them flat all the time. The only negative that I have heard is that some players who really like to "dig in" say that the clay is too hard. But that just means it is doing what it is supposed to do and that is to eliminate those holes from forming.
Here are some pics of the installation: