I'm not really a fan of BBCode in PHP Fusion.
It doesn't follow the same coding logic as the majority of the site, and IMHO, needs to be entirely overhauled or thrown out.
From what I can see, Bootstrap is not currently supported for BBCode within PHP Fusion 9. which makes it difficult to use Responsive div/class types within things like the forum and comments.

On other pages such as articles and news, I can use code for images and videos and make them responsive by using code such as:

<center><img class='img-responsive' src='URL' alt='LABEL'></center>

<div class='embed-responsive embed-responsive-16by9'><iframe class='embed-responsive-item' src='youtube url'></iframe></div>

Are there any plans to bring Bootstrap functionality into BBCode Land?