This was discussed a long time ago back on page 8, I apologize if it was beat to death, I have not read all 20 pages of this thread.
To get the DFT setting I want I have been putting an O-ring pick between the set screw and fin to push fin forward enough. I bought some Nylon tip set screws from McMaster-Carr to fix this. YES, I know if the fin is really snug the nylon could compress a little as I am trying to make adjustments. That is a minor inconvenience. I had a professional machinist drill out the block where the set screw tip pushes DFT forward (A).
I now have a new minor issue that was unexpected. The fin will not move more to the front because the front setscrew (length adjust screw) is contacting fin. I plan to have my machinist friend remove 0.15-0.20” from this spot to make clearance (B).
Part # 90291A407, 5/16-24 x ½”. A little longer would have been better but they only had 0.5” or 1.0” length.