About 1962, Dad took this New Yorker out the Lake Street L, and I recall the crew raising the trolley poles when we descended to ground level. I think I can safely say that that was never true on the New York Interborough. The BRT or BMT routes that had service by poles at the far ends of third-rail routes were probably (error possible), Jamaica, before the construction of the el, Metropolitan Avenue, before the extension of the el beyond Palmetto Street, Canarsie to the pier, Culver and West End before el construction.
I suspect that your answer to when the last Brooklyn el train used trolley poles is on nycsubway.org by inspecting the history of each line.
Therefore (subject again to error), I'll claim that Shore Line in East Haven has these New York rapid cars with poles for museum duty, but they never had poles in New York service:
low-V 5466, Independent 1689, redbird 6688. According to the web page at bera.org, Brooklyn 1227 and 1389 saw service on the combined routes: with third rail, then changing to trolley poles as in Chicago. What puzzles me about the street-running Brooklyn service is that the platforms on Jamaica Avenue, Jamaica, and New Utricht Avenue in old photos are low platforms. I don't know about traps and steps.