With the mixer on raclette I have less need to stop the batsman to scrape myself preparing the items that remain unmixed at the edges. It's not 100% effective, but much better than regular drummer.
The height adjustment of the drummer is done through the screw at the joint of the arm when it is raised.
ONE TOUR WITH ARMS TOO LOW AND YOUR NEW DRUMMER IS DAMN !!! Be very careful, check the setting by turning very gently by hand and checking property: any gray mark on the tip of the beater means that it is too low.