Theravada and Nagarjuna

I appreciate that various aspects of Nagarjuna's teachings are rejected by Theravadans but I'm wondering where the line is drawn. For some of his teachings I can see room for scepticism, but what about his central argument? Four questions... In his *Fundamental Verses* Nagarjuna demonstrates the absurdity of positive or extreme metaphysical positions. Do Theravadans accept this proof as valid and sound? Do they accept its result, which is the logical absurdity of extreme views? If they do accept this logical result, do they also accept the falsity of such views? If they do not accept N's argument, on what grounds do they not do so? EDIT: Perhaps I should have asked just this. Is it possible to endorse the logical result of Nagarjuna's argument in *Fundamental Wisdom* and remain a Theravadan?