The fade togglebutton should show for the Default, untextured brush.

source/blender/src/buttons_editing.c

@@ -4174,6 +4174,7 @@ void sculptmode_draw_interface_textures(uiBlock *block, unsigned short cx, unsig
 	}
 	else {
 		uiBlockBeginAlign(block);
+		uiDefButC(block,TOG,B_NOP, "Fade", cx,cy,50,19, &sd->texfade, 0,0,0,0,"Smooth the edges of the texture");
 		uiDefButS(block,NUM,B_NOP, "Space", cx+50,cy,65,19, &sd->spacing, 0,500,20,0,"Non-zero inserts N pixels between dots");
 		cy-= 20;
 		if(sd->brush_type == DRAW_BRUSH)