Actually we have a template engine now and the HTML stuff is going to be more and more outside of the classes.
I must admit that embedding HTML is very oldskool but does the job straigthfully if you consider that the main look and feel is done by the theme.
However this obfuscates the code.
In fact, the template engine has been ported from phpbb when we ported the forum. So we are able to use the phpbb theme as is. Now the template engine has been refactored out of the phpbb module and can be used by the whole application.
It is possible to store a theme in the HTML module, so at the end we have a very flexible solution