Here a little trick that can help you
The use of the cool plugin by Thomthom Components Comparison
As there are not yet system of instancied Objects / Group in Moi3D for export to Sketchup we must make a little tricky thing!
Say I have 2 Objects (here a cube duplicated) in Moi3D, I export them in 3DS Format
Import in Sketchup / Explode one time
so we have 2 Components triangulated named OBJ1, OBJ2
Launch the Components Comparaison and Bingo we have now instancied Components!
Triangulation can be cleaned by plugin Clean Up
by Thomthom again!
Result will be the same with 2 different cubes but with the sames dimensions!
With more complex objects there is something more to make!
That is failing or one object is rotated!
this you must just find the good tolerance
inside the Thomthom pluging! Don't hesitate to push it!
Of course many object can be treated in the same time as Shown in this Chri's Video!
The start Moi3D objects (fixed image)
Process in Sketchup!