I completely agree, and have come to this same conclusion as well. When discussing plans for having 3D microbes in the Macroscopic stage, I was coming from the point that we would already need the LOD system for the rest of the stage, and that adding in 3D low LOD microbes would be a natural extension on what we would already have. It would not need to be done immediately however.
Hhyyrylainen is rightfully concerned about the difficulty of implementing an organism LOD system in Godot, so perhaps we just need to decide on the ordering on which this system is implemented in. I don’t think that we can define a small enough scale range to have the entire Macroscopic stage work without a LOD system without greatly compromising it, but that does not mean that we can’t first focus on implementing a specific or compressed scale in Macroscopic that all organisms will fall into. Instead of having a fully functioning LOD system be a requirement at the beginning of development on the stage, it could instead be placed into a later goal for Macroscopic.
I do want to mention here that I am already developing a LOD system for the world generator. It is currently only designed for managing terrain mesh chunks, but I have plans to extend it to manage associated static entities such as rocks and foliage. The foliage would include the sessile organisms described in this thread The Sessile Question - #20 by MirrorMonkey2.
A separate LOD system might be better optimized to handle organisms that are immobile, but not anchored to the World, such as phytoplankton. This system could eventually evolve into the full mobile organism LOD system, but it could start by simply managing immobile plankton. Non-motile single cell phytoplankton would be ideal to begin this system with, and is why I proposed it earlier.
So to clarify, I am already planning on designing this system anyway, and it should be quicker to design once I have finished the World Generator’s LOD system. I would think that the plan would still be about the same if I was not already working on the system, it would just be that the LOD system might have to wait for the end of Macroscopic stage until it is implemented.