James, I still have hope that I can train my pinkie. I’ve been doing pinkie drills, finger gym exercises and now legato drills in Grade 3 for about 6 months now. I still can’t hammer on with my pinkie on an acoustic guitar, when pressing down with the first or index finger, but I can get some sound on an electric. I can use the pinkie to hammer on Dsus4 chord from the D chord on acoustic.
Just for fun and to show my documentation of my pinky shortcomings here is a link to the picture I posted almost 1 year ago in Module 4 finger stretching discussion:
SteveL finger stretch hand picture
At least with my short stubby fingers I can bend strings on an acoustic and bend strings 3 semitones at the 5th fret highest E string string with my Strat strung with 10s.