TRUE Smarty will merge the compiled template
code of subtemplates into the compiled code of the main template. This increases rendering speed of templates
using a many different sub-templates.
Individual sub-templates can be merged by setting the
inline option flag within
$merge_compiled_includes does not have to
be enabled for the
$smarty->merge_compiled_includes = true;
This is a compile time option. If you change the setting you must make sure that the templates get recompiled.