Properties pane for Failover LoadBalancer EIP doesn't provide GUI control to set "roundRobin" attribute

Assume a route like this:

<route>
<from uri="timer:timer1?period=1000" id="Timer">
<description/>
</from>
<loadBalance>
<failover maximumFailoverAttempts="1" roundRobin="false"/>
<log message="Log1" id="Log1"/>
<log message="Log2" id="Log2"/>
<log message="Log3" id="Log3"/>
</loadBalance>
</route>

I want to edit the loadBalance EIP to set roundRobin="true", like this::

<loadBalance>
<failover maximumFailoverAttempts="1" roundRobin="true"/>
...

I do not believe the GUI lets me set the roundRobin attribute for the failover LoadBalancer. (There is a RoundRobin type of LoadBalancer, but that's different than the roundRobin attribute of the failover LoadBalancer). The screenshot attached shows the attributes I can set for the failover LoadBalancer, including "Exceptions" and "Maximum Failover Attempts", but not "roundRobin"