Can anyone explain the registration process in Spark

I'm trying to overwrite the registration process and having some troubles, does anyone know of any links with better explanation regarding customising Spark ? I feel like the documentation is so bare.

So I am overwriting the method register in the RegisterController, thats fine, I can see my custom method running - however I can't quite find where this method is called from because I need to inject the Request into it - essentially I am trying to get the current route path in this register method, but something like Route::currrentRouteName() is empty, so I thought I might be able to use the Request to get it, but I just don't know where its called

Any pointers appreciated