Action redirects to self

I believe we talked about this but don't recall the outcome.  Is it 
valid for a performBlocking Interaction to return a properly encoded 
action url [i.e. either a templated url or a consumer rewrite token  
string] as the redirect url if/when the portlet's action wants the 
action result to be a redirect back to itself via the current page?  If 
its valid (in 2.0), was it in 1.0?  Did anyone implement/support this?
    -Mike-