I've had inconsistent results as well with the auto-disk setup when it comes to small charges, i.e. 3 grains or so. The adjustable style charge bar works very well, and saves a lot of time as well, not having to change out disks when switching powders or charge weights. This is where a good scale comes in handy.
I've been loading for 20-plus years, and recently started loading .380 for my wife's gun since I couldn't talk her into a 9mm. Dies were hard to come by with the recent panic-buying, but finally found some. I've used 9mm dies successfully, but with slight issues due to the expander die not reaching far enough down. 9mm cases also have a slight taper, but everything miked out okay and headspaced just fine, probably due to the brass springing out a little after being resized and, of course, after seating the bullets. Using the proper dies, especially the expander, makes it way easier!