I got it to work by re-adding it back as a Xenporta block
and editing the xenporta block directly.
Template: EWRblock_TaigaChatAlt
Code:
<xen:if is="{$visitor.customFields.taigachat} == 'off'"> <xen:else /><xen:include template="dark_taigachat">
<xen:set var="$taigachat_alt">1</xen:set>
</xen:include>
</xen:if>