When modelling component diagrams in UML2, is it permissable to repeat an interface on a component if it makes it easier to connect components? Such as below:
Any guidance would be most helpful. Thanks.
Any block that you see on the UML diagram, is merely a view of an object, that can have many views. How you are placing and cloning them is up to your convenience.
Only when creating new interfaces of the same name, be sure that you are creating new views of the same object (interface in your case). If you'll simply copypast your interface'in VP UML, you'll simply clone it.
What is interesting, later, on the class diagram you will have interfaces shown as special class blocks, not as here. And these will be also merely other views of the same interfaces you see now on your component diagram. At least, it is a good style to do it so.
So, yes, you can. It is the default behaviour.