After testing this a little bit, I am now also convinced that Simple Mode = OFF is the much better way.
Yet, I didn’t see any need to dive into flat files for Item creation, because both Paper UI and Habmin allow to do so from the web GUI, directly from the channel of the Thing. It’s in the same place as with simple mode enabled (big blue circle), or after expanding the section via Link channel → Create new item.
Awesomeness: this has given me control over both the label and the name of the item.
And in fact Paper UI’s default name now looks perfect to me - it does indeed use the label of the Thing as the basis. I like that much better …
And once the Item is created, there is this handy feature to copy the item name into the clipboard - this is awesome for filling my sitemap with content. I wonder would took me so long …Simple Mode = OFF for the win.