Hans, I don't think we have enough real factual information to know "what's next" after installing an aftermarket exhaust. Remember too that an aftermarket with the insert in is likely a very different animal than one without an insert.
Although many have posted their opinions only woolf, from what I can see, has posted any objective information.
I'd suggest doing nothing till we get some real facts (that's what I have done with my LeoVince full exhaust, and it runs just fine. And, I know that I can not possibly tell whether or not it makes my bike any faster than it was withthe stock exhaust.)