Perhaps, but what about ent_morphskin... we can sacrifice detail with distance, and this is a good way. And as I already said, the alpha decreases with distance.

Or you could have both trees, the hi poly and low poly there at the same time, and turn 1 invisible depending on distance.

Another would be a sprite rather than a low poly tree.

The problem is, I think his intention is to maintain the look of a forest even from a great distance.