When we import an obj an automated process can be initiated in the background so the insterted obj object can be saved as orbx with the axis positioning function and reimported as orbx.
What we will see is a final objects which is an orbx file. The save folder can be set by us automatically or choose the initial obj folder.
All this can be performed in the background with probably a small increase in the processing time but for sure it will simplify things as all the objects will be editable through the archicad plugin in realtime.
I think you could do this much easier in Octane Standalone. Input the OBJ into Standalone, attach to a Position and Geometry Out node, and save as ORBX.
I don't think you are going to get the level of automation that you are looking for in ArchiCAD. You would need to go to a higher-level 3d modelling app for that.
Paul