According to the documentation, it's possible to add multiple orgs to the Splunk Add-on for Okta. However, there is no supporting documentation as to how this is actually implemented:
Q: Can I associate multiple Okta orgs with a single Splunk App for Okta instance? A: Yes. As part of the Splunk Add-on for Okta, each modular input entry can be pointed to a new Okta instance. Just Add as many modular input entries as needed.
Has anyone successfully added multiple orgs to the app?