I have noticed the Z option where I can rotate the C-clamp and it works.
However my problem is slightly different- where I hang a fixture in 2d top plan following the red rhombus snapping position, which assume it should give a guide to where to hang an instrument, I then notice that in 3d view the C-clamp (with the fixture) is not hanging on the truss or pipe, but at the bottom, top or inside. I can actually see the I have problem mainly with trusses as with pipes seems to be working following the red rhombus guide.
So I was wondering if there is an option to facilitate the hanging of the instruments to make sure they match in both 2d and 3d. Obviously I can adjust the instrument in 3d, but it's a bit annoying as I usually position most of the lights in 2d view.