[kh99]

You could create a plugin using hook location parse_templates and code something like this:

global $show, $forumid;
if (isset($forumid) AND in_array($forumid, array(1, 2, 3)))
{
   $show['ads_forumid_variable'] = 1;
}

then change all your template conditions to be:

<if condition="$show['ads_forumid_variable']">

if you wanted to get fancy you could make the forum list a field in the settings, or you could even make it an option when creating a forum.