A way to achieve it can be using a Software Delivery package to run at the Agent and run the needed "caf setserveraddress" command after the Jobcheck finishes, as doing the change while the job is running can lead to unpredictable behavior.
Please, download the package setserveraddress-package.zip, uncompress it and import the package to the Software Package Library.
This package uses the User Parameters to set the name or address of the new Scalability Server.
When distribute the package to the necessary Agents create the Container using the option "Software Packages to deploy with custom settings".
On the new Setup Jobs window, go to the Jobs tab and then the Job Options tab where the User Parameters field is shown as in the following example where the new Scalability Server is set to "itcmss142":
When the job runs on the Agents, it waits for 2 minutes for the Jobcheck to end and then run the "caf setserveraddress" command to avoid interfering with the Jobcheck.