FWIW, the BD-3008 has its "selector" cut away, very much like the one shown in Claven2's photo. The BD selector is also free to move, but because of the cutout, this has no effect whatsoever on the disconnector.
Another option is to convert the selector into a safety. This can be done in a couple of ways. Claven2's first build had a disconnector confined to the central position, with a selector that either permitted foreward movement of the disconnector, or blocked it, to provide a safety position. A second method is to allow the disconnector to move to the left, but to have a block welded to the inside of the trigger box, so that when the disconnector is in the left position, it cannot move foreward at all.
Both of these safety conversions act essentially as trigger blocks; neither locks the sear.