I keep pieces that might be big enough to make knife parts in a separate area, keep them marked as to what kind of metal it is!
I always am doing other metal. Anything too small to be outright useful goes in the bucket. Like you say it adds up after time. Keep up with scrap prices and when they are high sell!!!
Honestly I have not tried Damascus at this time. However, the making of Damascus without cold shunts/flaws is hard enough with large pieces and having everything clean and smooth, to my understanding. Starting out with a bunch of small pieces is definitely going to add another layer into that process, of not having flaws and cold shunts in the process!! Just my O2 for now on that.