For me and my BR shooting SD is very important. Also I mark all flyers (true ones not trying to convince yourself otherwise)I take my chrony data at a minimum of 10 shots and a minimum of 10 outings in different days and locations.
This is all input into my app and I get good data from this. Just like using a chrony over an entire match, good data that shows how good your load really is.
A 5 shot string tells you very little, a 10 shot string isn’t much better statistically, but is better.
40 shot strings tell you what you need to know, especially the average velocity and ES. SD is not really important to me.
If you chrono all your cold bore shots, it might be interesting to see the ES/SD numbers for that data set.Cold bore mapping to me is just as important in determining ES and SD Especially if your a hunter. You want that confidence that the first shot, which is the most important to go where you expect it to. Just my opinion.