It doesn't matter, the edge of that blade seems to be mostly jagged (see picture below), so technique will not make much of a difference.I used a Derby Extra for the first time this morning that I know is pre-2016 because I bought the sample pack it came in about 10 years ago (as old as this thread, yeah?). I think I'm still bleeding. I have a tough beard and I'm used to blades having to settle in, but not like this. The broken glass analogy up above seems pretty accurate. I haven't had to pull the styptic out in awhile, but this morning it was my best friend. I'll give the blade another go and lighten up on my technique, but if I look like I had a one-night stand with Freddy Krueger again, in the bin they go.
I have tried with Derby Extras many different times using many different razors, and what happens is that eventually (after 4-5 shaves) your face will actually hone / smooth out the edge, at which point you will have a dull blade but without the nicks or weepers associated with it.