To someone who definitively knows, what exactly are the current PADI requirements regarding using a surface SMB and a dSMB?
Deploying a surface SMB is hardly a skill and could very easily be done and practiced in OW. Though not rocket science, a dSMB is a bit more complex.
@stuartv idea of adding dSMB to existing Adventure Dives would work if PADI would be willing to revise curriculum, that's probably not likely to happen. dSMB as a single Adventure Dive seems OK to me also. I did Deep, Nav, PPB, DPV, and Wreck when I did AOW, dSMB would have been at least as valuable as Wreck was as a single dive. Personally, I don't see dSMB as a freestanding specialty course.
My last PADI training was in 2005. Through OW, AOW, and Rescue, I was never shown, taught, or asked to demonstrate using a dSMB. I learned by watching other divers use a dSMB, obtaining equipment, and practicing myself. I did not have to demonstrate using a dSMB until I took the SDI Solo Diver course. On dive one, deployment was from the primary, on dive two, from the pony.