To improve the loading speed of your published site, the following would be effective.
Reduce the number of fonts used: Japanese fonts, in particular, take up a lot of space and their mere presence in the list can affect performance.
Reduce the number and size of images on the screen at a time: Images are loaded when they scroll and enter the screen, so placing them outside the initial screen will speed up the display.
Reduce the absolute number of boxes per page: it works better if you break up the pages, rather than cramming too much into one page.
Even after checking the above, if you are experiencing abnormally poor site performance, please contact our support via the chat on the bottom right.