Active Instances to stick with Old Version of Code - Post Deployment

In the situation where you do not have this defined yet, what you can do is define this variable/parameter at the sub process level with a default of 1, older parent processes (after you implement in the parent) will not send this variable, thus the sub will use a default of 1, where new parent processes WILL send in variable with version 2+, so it is achievable to implement this immediately but this method will not work for distinguishing between 2 legacy versions prior to implementation.

For your case, you might be able to achieve this by creating a process report for the parent processes with pp!id (instance ID) and pm!version. In your sub process, you should be able to retrieve the parent process instance id using parent_process_id(). You can then pull the parent version from your new report, based on this instance ID, and direct your sub process accordingly.

In the situation where you do not have this defined yet, what you can do is define this variable/parameter at the sub process level with a default of 1, older parent processes (after you implement in the parent) will not send this variable, thus the sub will use a default of 1, where new parent processes WILL send in variable with version 2+, so it is achievable to implement this immediately but this method will not work for distinguishing between 2 legacy versions prior to implementation.

For your case, you might be able to achieve this by creating a process report for the parent processes with pp!id (instance ID) and pm!version. In your sub process, you should be able to retrieve the parent process instance id using parent_process_id(). You can then pull the parent version from your new report, based on this instance ID, and direct your sub process accordingly.