I posted a fix for the Bitmap Fonts plugin on Linux here, it had to do with case-sensitivity. Not sure if the plugin is web-compatible but as far as I'm seeing it's not using Node APIs so it should be fine with applied patches on the web version as well.
The loading screen was used, it's just that the files loaded too fast locally. I managed to get it to show up after having to preload the bitmap font on Linux.
Nice work!