Your comments

As an aside - I'll likely rename them to something more intuitive, just a heads-up :)

As of 1.25, there are now two additional nodes to aid this - "Relay In" and "Relay Out" :)


I generally do it with all the example shaders at the moment

This has now been fixed in 1.25, thanks for the help in spotting the issue!

They should be. And there's no such thing as Unity 5.5 yet

This is a path I haven't dared to walk so far.

The problem with adding more control over the outline pass, is that people expect there to be even more options if I add just one option. For example, people will want to be able to change blend mode of the outline

I'll have to look into it, not sure what could be wrong

You can somewhat do that already by selecting the node :)