You can try what he (Nathan) does with 3v. I don't know if he does any pre-quenching, cycling, or other pre-hardening operations, but basically you go straight from quench to cryo (no snap temper), and use the low temperature tempers (avoid the secondary hardening tempers). The secondary hardening tempers rob carbon from the martensite to form carbides. While this aids wear resistance, it's not ideal for a chopping knife, where a higher apex stability is more important than wear resistance. The clincher is this, tho....with a fairly highly alloyed steel like 4v, the LN2 alone may not convert the RA% one might seek. That is why secondary hardening is almost a must for RA reduction on such highly alloyed steels, the LN2 doesn't convert enough of it (surprising to me). Sometimes 2 LN2 cycles are used, as in one post quench, and another after the first temper. That gives you an idea of the basics of the delta HT, but that was tuned for 3v, not 4v (or even M4). I had Peters' do the Delta heat treatment on a CPM M4 hunter for me a few years ago, and it seems to work great. But that's a hunter, not a chopper.