So from what I can tell each item has a specific strike/chop/jig point that will stay constant. So if walnut logs will have the same chop point on any walnut tree I am not sure. So far I know at least all grade 4 walnut trees have the same chop point for walnut logs.

What I am confused about now is that the example given in the patch notes makes it seem like you can force a specific item to drop while gathering if you have the right rank and stats. Is this not the case?