Please don't renounce the discussion. I certainly wasn't suggesting you did. I was trying to be helpful.
What you say here is spot on imo. But it misses a point. The Middle Way doctrine is a neutral metaphysical position and this is irrefutable in the dialectic. Of course, most metaphysicans don't consider such a position since it appears to be paradoxical. This leaves them agreeing with Popper, Carnap, etc. that all metaphysical positions are absurd. What Nagarjuna proves, however, is that only positive metaphysical positions are absurd, while a neutral one is not.
It's actually pretty easy nowadays to verify that all positive metaphysical positions are logically indefensible, since nearly all philosophers discover it and there is a great deal of literature. While it's difficult to make sense of a neutral position, it's not possible to logically refute it.
Popper, like Kant and so many others, believed that all knowledge of reality is conjectural. But they failed to falsify Nagarjuna's doctrine, so their own view is conjectural. The central claim of mysticism is that such knowledge is possible, and until we can refute this claim we are not actually forced to be so pessimistic.
The issue in the background here is that if we assume the universe is reasonable, then there must be a reasonable metaphysical proposition which describes it. If it is not then philosophy is largely a waste of time. Nagarjuna's view is therefore worth considering, for the immediate implication of his proof is that the universe is reasonable.