just as an ordinary list of suggestions:
- use LOD heavily,
- use as low as possible number of skins for a model (I saw you use Dexsoft models what I own too, they usually have too many materials),
- set passive entities to static, don't run while loops in too many actions (e.g. for vegetation),
- use close clipping of non-important entities (can be easily done if you make only 1-2 LOD files, if you use the external LOD system available below 3DGS Pro),
- use e.g. particle effects only close to camera,
- stop animations if entity is out of view,
- cover the clipping, and the very-very low poly far LOD models by fog,
- in Pro you could have access to terrain LOD, sprite instancing, and bone animation by shader, what I need but nobody promotes me to buy the Pro licence
