The idea is:
Add UML/BPD nodes designed to help document, understand, and perhaps ‘bridge’ n8n with currently manual/offline processes. These nodes would be simple information stores, that can be linked together using the existing n8n UI/concepts of linking, branching, iteration, etc.
Level 1: Add simple nodes to store as text repositories. By naming the nodes, and having simple fields / metadata like “Inputs”, “Outputs”, and “Process”, you can start to document manual steps in an existing workflow.
Level 2: Integrate UML/BPD nodes like Events, Activity, Gateways, Sequence/Message flows, Pool and Swimlane groups, artifacts etc.
Level 3: Add export to PDF/PNG for discussion, review 
Level 4: Add ability to turn these ‘manual’ nodes into a form, so that for a given node, you get a URL with the required inputs. Thus, at a certain point in an offline workflow, you can ask the responsable party to fill out the form, and then the workflow continues with the data from the form, acting as a bridge between offline and online/automated workflows.
The crucial difference between this and just building the automated workflow is that you retain visibility over the entire scope of the information flow/workflow.
My use case:
I am trying to implement automated n8n workflows for things that are currently manual business processes. I am documenting the processes in Draw.io/Google Slides, and wishing I could just do it directly in n8n so that I can directly replace the documented manual processes with automated solutions in chunks, while keeping visibility on the entire flow.
I think it would be beneficial to add this because:
Often, as a precursor to automating something, you need to first document it.
Once the current/existing flow is documented, understood, it can be shared, presented, discussed, and ultimately automated.
Indeed, a business is a collection of people with skills that follow processes that are often undocumented, just floating around in the collective consciousness. Wikis, Runbooks, etc. are all solutions to this, but they use a text narrative format to show linear processes, decision points, specifications for what each steps needs as inputs, and what it should output.
Getting businesses and organizations to start using n8n for a ‘library’ of documented business processes would directly lead them to want to test / use the automation features, thus creating an onramp for users to use advanced features, while already being familiar with the n8n ui.
Are you willing to work on this?
Yes