Set default connection properties and flat file

Is there a way of setting up Omnigraffle so that all new lines have all the connection properties unchecked? Also, is it possible to have all new files to “save as a flat file”. I have no figured out how to do this. I have noticed a behavior where if double click on a small icon at the top of the inspectors side bar, a small green lock icon appears. I have not figured out for the life of me what this does.

In general, option-click on a tool and then set its properties (of any kind). Those will be the defaults for the tool until you change them.

Set the file saving format you want in your default new-document template.

According to the help, “As you show and hide other sections in the same inspector window, the locked section remains visible.” That seems to mean if you show other inspectors using the View>Show Inspector menu or its keyboard equivalents, they’re added to the inspector window rather than replacing the current one in it. Clicking on another inspector’s icon at the top of inspector window window undoes the lock; the clicked inspector replaces the current one…