EasyDiscuss & bbcode editor advanced formatting

Hi,
Can someone tell me the other parameters that are compatible with bbcode editor and EasyDiscuss? I noticed the [center] parameter works. However, most the formatting mentioned here doesn't seem to work? https://forum.joomla.org/app.php/help/bbcode

For instance, the size formatting.

I would really like to use a better composer for a "forum" style and while bbcode is nice and lightweight, I think it lacks many features of modern composers.