Hi Emmanuel,
Ok, that' what I meant with "Have I missed something?" [;)]
setVisualProperty / getVisualProperty provides some mix of my approaches 1 and 2. I can use it to connect a container of additional data (approach 2) to the model and have no need for extending HomeFileRecorder to store them by myselfe but I would get the backdraw of approach 1 regarding deserialization on other machines as mentioned.

Regards,
Alex