Is it possible to create LODs for all zoom levels?
You can't, because if any of the three LODs is missing, BAT will create it by itself, during export. But you can create LOD5 and then clone it as LOD4 and LOD3 (use the Copy method, not Instance or Reference). However, LOD3 should preferably be a simple box (for performance); small props, automata, people etc are typically not visible in the farthest zooms anyway.
I want to create LODs for level 1 and 2, because I have diagonal BATs in water and at level 1 and 2 the water does not go close to the BATs.