Hey Dan, after Hidden analog mode got enabled I was able to finalise my set up. Manual open is working as well as automatic ring detection unlock
Final set up looks like this
3 - Ground Purple & Black
SW3 - Blue Cable (Top right pin on the open button as suggested in the other topic )
TR2 pin - Red Cable (As suggested in the other topic (GDX5 Intercom integration - #19 by danc ) (I have also tried Green cable and Yellow did not work)