Try 500 mg of magnesium glycinate. I came off of pramipexole due to augmentation and am taking this instead-it has helped as much as meds did. Also, have your iron levels checked, serum ferritin should be 75 or higher, well above the normal range. I joined RLS foundation, which has provided invaluable information, you might consider joining.
Best of luck - RLS is no fun, and people just don’t understand what agony it causes and how disruptive to your wellbeing it is.