s3d support is even worse than I expected when I first got mine. Most large 3d companies are lax, but this is silly. 4 years now and no implementation of a common piece of hardware that has an available API and 17 pages of +1s.
You may not like my implementation, but I do have a spacemouse working with s3d. I posted my solution last year on their forums:
It involves installing an older version of the 3dconnextion driver. That version has a gui ability to map 2d mouse commands into an application. As such it essentially acts as though you were using the keyboard mouse combinations that s3d currently uses. You do have to move your mouse occasionally to keep the cursor on the screen, but other than that it works as you would expect it.
Better than nothing. ..and as yet its more of a solution than 3dconnexion or s3d has offered.