Well ę in część is without the n never heard it with n, but I definitely use the n in words like jęzik, so yeah you cannot generalize between those nasals and "say n if it's in the middle of a word" only goes so far
Ą is a bit more regular at that, so usually loses the n when at the end of a word and never heard without n when in the middle of a word, except in places like Warsaw, and other cities up north, where I was called out as gòralski (which is funny considering I'm Italian, I guess I'm learning polish wrong but convincingly enough)
Ą is a bit more regular at that, so usually loses the n when at the end of a word and never heard without n when in the middle of a word, except in places like Warsaw, and other cities up north, where I was called out as gòralski (which is funny considering I'm Italian, I guess I'm learning polish wrong but convincingly enough)