I make knives. I don't see why you couldn't use an exotic stainless like ATS-34. When properly heat treated, it should hold an edge longer than most carbon steels. Rather than ATS-34 you should use 154 CM which is the American equivalent of ATS-34.
Better yet, is CPM 154 CM. Here is a description from the Crucible Steel spec sheet:
Crucible 154 CM is a modification of 440C martensitic stainless steel to which molybdenum has been added. 154 CM has better corrosion resistance, better wear resistance and better hot-hardness than 440C. For knifemakers, it offers better edge retention than 440C. It also has higher attainable hardness and better through hardening characteristics than 440C.
And even better than that is CPM S30V. It is very difficult to grind and polish after it has been heat treated, so most work must be done prior to heat treating. Here is a summary from its spec sheet:
CPM S30V is a martensitic stainless steel designed to offer the best combination of toughness, wear resistance and corrosion resistance. Its chemistry has been specially balanced to promote the formation of vanadium carbides which are harder and more effective than chromium carbides in providing wear resistance. CPM S30V offers substantial improvement in toughness over other high hardness steels such as 440C and D2, and its corrosion resistance is equal to or better than 440C in various environments.
These steels can be purchased from Admiral Steel. A direct link to their price list is HERE.
Take care,
Mike L