Separating the emoticons would help, as it could be made so that it would work on other places of the wiki. It could be used in Comments, WikiForum, inside a blog (via the BlogPage extension), talk pages, user pages, etc. It'd also have to require including a config which would accept a array of whitelisted namespaces.
@georgebarnick It does, but according to the documentation on https://www.mediawiki.org/wiki/Extension:WikiForum#Configuration, the text follows as:
$wgWikiForumSmilies - Array of emoticon text forms => image file names. This configuration variable will be removed in the future and replaced with a better system for configuring emoticons. Do not rely on it.
@ashley can provide more information on this.