I have been looking through InsightConnect documentation. While doing so, I stumbled upon a Orchestrator that meant to be deployed on-premise to send data to InsightConnect. Is there functionality of Orchestrator can be leveraged in automation without InsightConnect ?
Depending on what products you have you can use the orchestrator with built-in workflows.
For IDR, there are automation actions that can enable/disable users in Active Directory, or isolate a computer using the Insight Agent.
Other IDR workflows: Automation Workflows | InsightIDR Documentation
If you want to create your own custom workflow then that is when you would need an InsightConnect license.