These settings are related to "ulimits" on OS X. They are safety limits imposed by the OS. These settings won't have any impact on DSS performance. You'll actually need to increase them only if you get errors like "too many open files" or "insufficient system resources".
The settings can be changed temporarily by entering these commands before running DSS:
ulimit -n 4096 ulimit -u 4096
To change them in a persistent way, see: http://unix.stackexchange.com/questions/108174/how-to-persist-ulimit-settings-in-osx-mavericks