When I'm setting up my Pipeline, I can't go "here are some brand new tasks, please run them",

I think this is the main point. Can you create those Tasks via Task.create and get what you want? If so, then sure you can do that:
` def create_step_task(a_node):
task = Task.create(...)
return task

pipe.add_step(
name="stage_process",
parents=["stage_data"],
base_task_factor=create_step_task
) `wdyt?

As for the node, this confusing bit is that this is text from the docs which seems to suggest that the node will be fully initialized before the callback:

yes the node but not the Job, so that you can have control 🙂