Hi,
Unfortunately, there is no way to reduce the loading times, other than splitting the objects into even more wto files. We in general recommend having around 10 object per file at the most, specifically because the loading times might be too high afterwards. However, as the loading process is done asynchronously, so it should be possible to display some other content or perhaps some instructions until the file has finished loading in the background.
Best regards,
Alexandru
Nilotpal Biswas