Got one on mine- was put there to solve a headshake handling problem 2 years ago. In reality the only thing that needed sorting was the springs and oil but bearings were done and new front wheel etc fitted and still it wasn't solved despite being tested by someone who should have known !!
Anyway at beginning of year AJ had a look and asked if i'd got water instead of oil in there
That sorted and the handlings been fine since (till i messed with ride height)
Anyway that changed and although it's still on the bike it's never switched on. I suspect it has some small effect just as it's there really.