Hello ,
Thank you for posting in the community. Could you let me know if you are trying to render an image or a video as this would make a big difference especially if the video is long. If you want to split up the rendering by clips an select export PNG images for videos instead of a MPG format if needed. This is found in the Export > More setting under the video Icon.
If you are rendering one image and it's taking 16hrs, there could be something wrong with the computer specs or a something else in the file that we would need to investigate. You should contact us and report a bug if that is the case: https://twinmotionhelp.epicgames.com/s/case-community-page
Kind regards,
Vincent B.