i think its enough to remove the hidden parameter tbh
<UnitStatType InternalName="UnitStat_CritDamageMultiplier">
<DisplayName>Crit Multiplier</DisplayName>
<DisplayNameShort>CRIT</DisplayNameShort>
<Description>The multiplier applied to the damage amount when this unit does a Crit.</Description>
<Icon>Stat_CritDamageMultiplier_Icon.png</Icon>
<Hidden>1</Hidden>
<DefaultValue>2.0</DefaultValue>
<UnitStatGrouping>CombatStat</UnitStatGrouping>
</UnitStatType>
remove hidden and you should see it