from what I gather there is a lightly documented concept

Yes ... 😞 the reason for it is that actually one could do:
` @PipelineDecorator.pipeline(...)
def pipeline(i):
....

if name == 'main':
pipeline(0)
pipeline(1)
pipeline(2) `Basically rerunning the pipeline 3 times
This support was added as some users found a use case for it, but I think this would be a rare one