Just curious but why the desire to use Unique instead of another powder if you have problems with it in your PM? A good load? I got away from using Unique and now use only sperical or ball powders partly because they meter so well. I use Redding Competition 10X Pistol PM for smaller charges (3-15 gr's) and Redding Competition BR30 PM for large pistol/small rifle charges (16-30 gr's). Use a custom Neil Jones PM for large rifle charges (above 30 gr's).
Suggestion: For ANY powder measure, find and install a baffle in the powder hopper for more uniform charges (if it doesn't already have one)!
Good shooting and be safe.