When working in vectorization mode, you can only add new nodes after the last node on the edge. You can use the Insert command from the context menu or a button with the same function to add nodes anywhere, but this can be very inconvenient when inserting multiple nodes. Adding a new node near an existing node can disrupt the selection of that node instead of creating a new one. The Insert elements mode allows you to get around these two problems. This mode has two main advantages:
When using a keyboard, the Insert elements mode is activated by depressing the "a" key on keyboard and holding it depressed while clicking the primary mouse button on desired place in the work area.
For devices without a keyboard, use the menu (create/edit mode) > Edit > Insert option, or the Element Mode button on the menu bar to activate this mode.
Inserting new nodes is especially useful when adjusting automatically created connection between objects or for creation and editing of special shading effects with manual stitches. If large number of manual stitches is created, it is also helps to avoid selection of existing node instead of making a new node.
Below example illustrates insertion of new nodes. Polyline ends with point (E). We want to insert some nodes after the node (2). Select point (2) by clicking it.
Activate Insert Elements mode. Click where you want to place the new nodes. Create new nodes (3),(4),(5),(6) and (7). Then exit Insert Elements mode. Notice that these new nodes have been inserted in the middle of the node sequence after node (2). The dotted line in the image below shows the previous appeareance of the polyline.
Note: while Insert elements mode is active, you cannot select existing nodes. To do so, exit the Insert elements mode first (release the "a" key or uncheck respective option in menu).