@bosquebill All through 2.10 (when the new drop shadow was introduced), I used "Drop shadow (Legacy)" for that reason: I wanted to be able to modify the shadow, either its position or opacity.
But in 3.0, with non-destructive filters, I'm using the new drop shadow since you can change an ND filter at any time. Non-destructive editing is one of the huge new features of 3.0.