I believe the code youo're trying to use, only works for played matches. and would work for you like this
<widget class="text" font="label" id="refp">
<translation id="text" translation_id="441094" type="use" value="Refereed by[COMMENT: referee, use top 10 matches, no person variable here, it's just a title, the referee's name is appended directly below this title]"/>
</widget>
<widget class="person_button" id="pers" font="value">
<record id="object_property" get_property="FRef" />
</widget>
not sure if it's possible to "see" the ref before the match is loaded and ready to be played aka the pre match screen as it's place it seems to work