Unfortunately no, it is not possible to change the LOD settings. I asked for this a long time ago for similar reasons to you, but it did not make the change list.

One other factor you should be aware of in using LOD is that the LOD ranges are calculated from the origin of the entity. For this reason it doesn't work too well with something long (for example, a railway train entity) which moves towards you. You may want to measure the performance increase of using LOD, I found it was not that large for my level.