What is the negative of not dropping the elbow?
Just my two non-expert cents. If you drop your elbow perfectly straight, no problem, but it adds a variable to the stroke that can go wrong (hello, me). Second, ff you drop your elbow and it pulls your shoulder down with it, you've added another variable to the stroke that can go wrong (Jasmin is all shoulder drop, but hers works). Anyway, I just think there's value in a training aid that teaches your brain to
minimize elbow drop, which ideally minimizes shoulder drop, which adds up to a more consistent stroke.