A pipeline is an asset: a definition you can edit, duplicate and check into source control, built in a node graph with a palette, a Check button and a Run button. Your surface is exactly as powerful as ours — our own voice-over pipeline runs as a user-editable definition, and the hardcoded version was deleted.
The node library is found, not listed. Every installed Forge set contributes its steps automatically, any BlueprintCallable function on an editor subsystem becomes a node, and so does a Blueprint function library in your own project. Installing a plugin adds its nodes with no edit to ours.
And the same definition runs headless from a commandlet, with no editor UI involved — so overnight batches and continuous integration need nothing added. Write it once; run it from the graph, from an agent, or from the build farm.