Paul,

I think most people who post here understood your post & how choke tubes (flush or extended) are installed & I agree with you that extended tubes look absurd on a SxS or basically anything other than a dedicated competition gun for that matter.

If the thought was to use extended tubes to move the balance point of the gun forward to make it more suitable for sporting clays I can think of several easier & more appropriate ways to accomplish that but I'm not really positive what benefit the OP was expecting.