Spline Mesh Customization.

So I created a blueprint following multiple tutorial. The bluprint is a spline that when I extend create additional mesh to fill the gap.

I have two main problems: the first one is I would like to be able to have 3 mesh in my spline. One to only be the first one, the second mesh only for the meshes used in the middle and the last one to only be use at the end of the spline.

The second problem is : If I move the gizmo to add meshes it will not add a mesh unless there is enough room for the full object.