I’m affraid ‘Balts” are not an ethnonym but a geographic name. Baltic is from Latin and means “belt”. Eastern Balts are rather finno-ugric ethnically (based on the phenotypes). I think some Belarusians don’t wanna be associated with Slavs since, first Slavs are politically attacked, second they don’t wanna be associated with Russia and Moscovits. That doesn’t mean that Belorusians have to refuse their ethnic origin. Slavs are a great people no matter where they live and what their enemies do!  8)