ZDP-189 should be able to hold a good edge with as low as a 15dps angle easily. You may want to determine the current angle and still with that though as ZDP-189 is a hard steel that will take time to reprofile. VG 10 is used with a 15dps angle by many chefs. You are using it for heavier task though and may want a greater angle to increase edge strength and reduce the chance of chipping. A double bevel can give some of the advantages of greater and lesser angles to an edge in some people’s opinion and definitely makes touch up easier once the initial angles are established.
