If the blade steel is the heart of a knife then the heat treating is the soul. The best obtainable tool steel in the world will make the worst very expensive custom knife if the heat treating is not right.
I decided years ago that to be able to control the quality of my knives I had to do my own heat treating.
The high alloy steels mentioned above can be tricky to heat treat and require good equipment that is capable of repeatability. Doing my own heat treating was a big commitment but I'm glad I made the effort and investment in equipment.
I can now precisely control the hardness of each blade. They are all individually Rockwell hardness tested through each step of the process. Final adjustments along the way can be made to arrive at the final hardness desired and the confidence that they are exactly right for the intended use.
I do an ultra subzero secondary quench in liquid nitrogen to insure complete conversion to the Martensite phase of the steel. This also insures stability and toughness for the life of the blade.
The quenching is followed by multiple tempers to insure the best balance between toughness and hardness.