Seems I forgot a few things. If you do a custom LOD, how do you melt/bake several geometric forms together into one again?
It depends how they are made: for example, if you have made a box and want to connect it to a cylinder, then convert both objects to a mesh and click 'attach' under the 'edit geometry' rollout - there may be some messy geometry, but it is by far the easiest way and LODs don't need to be prefect as they have no uvw settings.,..
This is it. Thank you for the quick help.