While nodes insert into the flow when dropped onto a connection line between nodes, the functionality still does not match when you select a connection line and insert nodes by keyboard.
When a workflow node is selected prior to keyboard entry, the program makes a new connection as you would expect. However if a connection line is selected the new node not only isn’t inserted into the flow, but is typically placed far off from the target area and difficult to find on large workflows.
This functionality would really simplify node insertion for those of use who prefer keyboard shortcuts / macros to the much slower drag and drop approach. For some reason I thought the change was slated for the 4.7 update, so I just wanted to keep it on the radar.