As far as I know, each meshpart loads in via an HTTP request. How can I speed up their loading for my project—so far it requires 28,000 meshparts with unique IDs—based on this?
If the meshes are flat, try setting them to Box CollisionFidelity and Performance RenderFidelity. This should help a little bit. You also might be able to use parts and wedges instead of meshes.
The FPS in the game itself is fine when everything loads, but it takes a very long time because each of those little dots are unique meshParts(all of them have their own MeshId). How do I address that without decreasing the number of unique MeshIds?