I can't see how you could keep JW friends after you leave. It's a conditional "friendship" based on adhering to the cult. What could you talk about with a faithful JW, other than idle chitchat? And how could you be friends with someone who views you as "worldly", in all that word's negative connotations? Someone who is basically viewing you as beneath them, and not one of the pure and favored? Someone who will be destroyed in the Big A with the JWs smugly cheering that on?
They're not really friends anyway. They're people who happen to be in the KH and that you chum around with because you have no other choice because if you didn't chum around with them, you'd be a friendless loner. And if you say or do the wrong thing, you'll be a friendless loner within the KH.