Posted by not done it yet on 12/04/2019 21:00:32:
You will only need the reverse for running off-load – unless you have some means of preventing the chuck from unscrewing!
If the chuck's done up tight, you need quite considerable resistance to make it unscrew. I used to sand and polish wood quite heavily in reverse as well as forward on the Speed 10 I had, without ever having that happen. It's also sometimes easier to get a knife tool at an angle to the the far side of a workpiece and chamfer the face in reverse.
Probably not heavy screwcutting, though… 