Managing connectors in Enterprise Architect can be laborious. You can only work with one connector at a time and you have to go through multiple dialogs to address all of the connector's properties. This tends to interupt your "flow" as you handle the numerous manual tasks necessary.

MGU, on the other hand, lets you address numerous properties and characteristics for multiple connectors at the same time. The image below shows the Diagram Connectors tab populated with all of the connectors from the currently opened diagram in Enterprise Architect. As you can see, you can check any number of them to work with. At the bottom are the tasks that you can apply to each selected connector.