Relievers used for reversibility test

Even though I'm being referred to RBH who will do loads more tests, the cons I've just seen wants to do another reversibility test.

Though I am reasonably sure they won't give up on me this time if it shows nothing, I would like to maximise my chances of this test showing something, if there is anything to show! Last time it didn't and I'm wondering if it's because they used salbutamol which I've never responded to that well (though oddly it does make my PF go up a bit, which somehow didn't happen in the test).

I saw on the form they said to use salbutamol again on the test; presumably it's the default. Is there any way of getting this changed, maybe to Atrovent which seems to work better (best of all is a combo but doubt they could do that)? I didn't really have a chance to explain about this in the appt and only saw the form once I'd left.