NotebookLM's Mind Maps were useless to me until this one update changed everything

NotebookLM's Mind Maps feature received its first meaningful upgrade over a year after launch: users can now customize maps with specific prompts via a pencil icon in the Studio panel. Previously, auto-generated maps became unreadable with many sources, surfacing every possible connection at once. Prompting lets users focus the map on a specific concept or thread, making cross-source synthesis actually useful. One remaining limitation is that maps still can't be edited directly inside NotebookLM — nodes can't be dragged or renamed — requiring an export to tools like XMind for deeper restructuring.