One can dream...
Actually I'm determined to do a bit more than dream. But my view is that the Bakerloo line must intersect with the Forest Hill train line, either at Forest Hill, Honor Oak Park, or New Cross Gate. By bringing it underground the southern of those options makes more sense. Connecting with existing transport hubs makes a lot of sense, and Peckham Rye, Catford, and to a lesser extent Forest Hill are the three big ones in SE London.

Bakerloo extension should be the 176 route or the 63 route or something in between. But any extension to South East London would be of benefit to all in SE London.