A: Great question ! Most of our knobs have a short screw to work with our posts. However, right now we do have one knob with a long enough screw where that application will work - and that is the Stewart with the Long Screw.
High end window treatments are meant to have a return or a projection from the wall and the knob with a long screw isn't ideal for a couple of reasons. First, we didn't like the way the naked screw looked - it doesn't give a finished look - Secondly, the metal screw could damage some fabrics. Another problem is stability. The fabric is too heavy for a screw alone to support it so for these reasons our posts were created - to provide a projection. Typically a projection will be 3.75" to 4". In some cases when the treatment is going over blinds or drapery panels or shutters the larger projection of 5.5" to 6". We both lengths in our posts.
However, sometimes the projection just won't work with some treatments, therefore, you could use our knobs with the short screw along with an Auger Screw Plug as long as you don't hit wood or anything behind the sheet rock just notify us that you need them and we will include them with your order. This would provide a little stability but it will be pretty flush against the wall.
Hope this helps.