I've completed 'Blind Betrayal', and Danse roams Listening Post Bravo, but when I initiate dialogue, he replies generically with "You're one hell of a solider." or "You're making the Brotherhood proud." Dialogue options are never presented.

Did you convince The Elder to spare Danse? I assume so, if you did, try fast traveling away and then coming back.

My mistake. I hadn't turned in 'Blind Betrayal' because I didn't want to bug out P.A.M. before completing Railroad quest chains. Turning in 'Blind Betrayal' allows Danse's recruitment.