Hello and welcome to the forums,
I would like to create the JCL once in test and be able to copy it to all production regions without changing it for each production region.
If the proper naming standards are in place this may be accomplished quite easily by putting all jcl in cataloged PROCedures and having a symbolic parameter to identify the environment (i.e. test, uat, qa, prod, etc.).
Done properly, the only differenc between a production execution and some other execution is the job name and the environment parameter.
I have spent years convincing organizations that changing the job stream as part of every promotion means the first production run is actually just a test. . .