Drop shot rigs have been used in the bass fishing crowd for a long time. The basic problem I see with it for fly fishing is the weight. Drop shot fishing requires a weight heavy enough to keep the rest of the rig in place.
Originally, it was fished on a tight line, so the lure would be suspended and the angler had a direct connection to the lure. Extremely effective at feeling subtle bites on small lures, but a pain when the fish got wrapped up in the drop line.
You're going to find the line, from the fly to the weight, will have ripped scales off the fish and can get caught in the gills.
It's why I stopped using the rig soon after hearing about it and trying it a couple of decades back.