Load multiple files fast

Questions
4

Something looks out of place in your description. You say loading as a single file takes 3-4 seconds, but as multiples it takes 30-40. Really think you need do profiling as others have said. Chromeseems best for that.

There is also another way. That is SceneLoader.

BABYLON.SceneLoader.Append(url, "file1.glb", scene);
BABYLON.SceneLoader.Append(url, "file2.glb", scene);
BABYLON.SceneLoader.Append(url, "file3.glb", scene);
scene.executeWhenReady( () => {
    // do stuff
}

I never do .glb files. This works for .babylon files & think it should work.