If you're experienced with making damascus, and have never used 15N20 and 1080/1084 mix, you're gona slap yourself on the forehead and say "Why did I do this sooner?!" when you use it. The two materials are so compatible that you can literally tie a knot in a billet, and won't get shearing or delaminations. Heat treating is very easy.....austinize at 1550F, quench in oil, and then temper in the 400-450F range (depending on what level of hardness you're seeking).
Using pure nickel has always been one of those "trade offs" we all face as knifemakers. Those folks you mentioned (I've been around long enough to have known most of them) used it specifically for the contrast effect it offered....but I can remember Bob Engnath telling me once that he wished he could find something for contrast besides nickel....simply because of it's impact on a blade's cutting ability. He knew it then, but at the time none of us had ever heard of 15N20.....now a days, it's considered the "standard" for most non-stainless Damascus applications.