Everyone would benefit from this update. It's nice that product owners can only create products withing their product line. However, on a related topic they should not be able to create a new workspace. The creation of a workspace should only come from an Aha! administrator.
Thank you for the idea. Today, you must be an Aha! Roadmaps administrator with customization permissions to configure workspaces and workspace lines. The status of this idea was out of date. You can learn more here: Workspaces and workspace lines.