I was also curious if I've missed an easy way to mention required packages for the controller, like you can do that in components (by providing

packages=[...]

).

I think you can do this using https://clear.ml/docs/latest/docs/references/sdk/task#taskadd_requirements
I'm not sure how the pipeline controller is handled but it still should be regarded as a task on a deeper level.

Meaning that you might need to use task = Task.current_task() and then task.add_requirements(package_name="your_package_name")
https://clear.ml/docs/latest/docs/references/sdk/task#taskcurrent_task