Enable placing an action on top of a line between 2 other items

[MatsOlsson]

Hello!

When building objects and processes you sometimes realize you missed to place an action. 
The intuitive way for me to add an action earlier in the object/process:

1. Select what needs to be moved to make room and move it.
2. Place the new action where it is supposed to be.
3. Configure the action.
4. Draw new connecting line.

Step 2 is not possible in the way the tool works right now. If you drag a new action and place it on a line between two other actions, it simply disappears. 
Currently I place the action next to the line. Then drag it on top of the line and then finish the steps.

Please allow us to place actions directly on top of the connecting lines.