I don't seem to be able to set up inherited Idea workflows.
I like that you can set up one workflow for a product line and have all the child products inherit that workflow. Because Ideas don't get created at a product line level (which I think should be changed, I really want that functionality), it seems to have been missed in the inheritance feature to include Ideas.
You can now configure workspace templates, including workflows for all records types. Apply a template to your workspaces to manage the settings in one place. Learn more.