Yes, you can do so, but you have to log in to S4 via SSH.
You haven't answered HOW to do this. What to modify. Which settings to change.
One way is to change the setting on the fly via the screen session, mainly to test it.
1. SSH to S4, Login root/admin. (I use putty.)
2. Type "screen -r" to enter the running screen session, assuming it is running with default image and settings.
- While in the screen session, many messages will go by. You have to read through them.
3. Type "P" to enter Pool Management.
4. Type "C" for Change Management Strategy.
5. Select one of the following: "0"-Failover(default), "1"-Round Robin, "2"-Rotate, "3"-Load Balance, "4"-Balance.
- Load balance requires quotas to be setup first. Balance uses equal share across configured pools. Read the cgminer readme files for more detail.
6. Press Enter key to exit Pool Management menu. Should now be back at main cgminer menu.
7. Exit screen session by issuing "Ctrl-A", "Ctrl-D". (Hold down Ctrl key, press "a/A", then "d/D".
8. Now back at shell prompt.
Hope this helps.
-Scott