Hmm, the template PAGE_CONTAINER is probably the right one.
HTML:
<title><xen:if is="{$title}">{xen:raw $title} | {$xenOptions.boardTitle}<xen:else />{$xenOptions.boardTitle}</xen:if></title>
So I tried changing that to...
HTML:
<title><xen:if is="{$title}">{xen:raw $title} | {$xenOptions.boardTitle} Additional Title Words<xen:else />{$xenOptions.boardTitle} Additional Title Words</xen:if></title>
But the title didn't change whatsoever.
What am I doing wrong?