Duplication items in drag-onto-image question

1. Moodle question drag-onto-image was designed as a matrix for drawing structural diagrams.
2. Dragged elements can be duplicated on the result diagram.
3. When user dragging the same element onto its image on the result diagram, the following happens:

• element is duplicated in the selection elements bar
• the cursor is moved to the right relative to its working area during dragging

An example is presented on gif