I notice that the answers you've gotten so far have been based on DE adjustables, although you were asking about an adjustable injector.
I do have an adjustable injector that I haven't tried so far. Frankly, it makes me a little nervous. The adjustment on these changes how close the safety bar gets to the blade. The thing is that although the resting position of the bar changes, it doesn't seem actually to lock into place, it will still move if you press on it with your thumb. It looks like it's designed that way, not actually broken, but it just seems odd. I like my non-adjustable injectors, though.
"...when I attempt a discourse the words come out as they will, and they may make sense when they strike the atmosphere, or they may not." O.Henry - - "Cabbages and Kings"