Hi folks --
We've got an arcade expression to distill a set of status fields into one so that we can have a more simple unique symbols renderer for our layer in the map.
The arcade expression has several if statements that result in 4 possible outputs. BUT two of these outputs are very uncommon occurrences - the data is being updated through a geoevent feed.
So my question -- is there a way to add values into the possible Types for the Unique symbols renderer?

Here's the arcade...
if($feature["FLASH_STATUS"] == 'Comm_Failed' || $feature["FLASH_STATUS"] == 'On') {
return "Flashing or Comm Failure";
} else if ($feature["PREEMPT_1"] == 'On' || $feature["PREEMPT_2"] == 'On') {
return "Railroad Preemption";
} else if ($feature["PREEMPT_3"] == 'On' || $feature["PREEMPT_4"] == 'On' || $feature["PREEMPT_5"] == 'On' || $feature["PREEMPT_6"] == 'On') {
return "Emergency Vehicle";
} else {
return "Normal";
}
I'm thinking I can edit the source data for this one layer in this one map, but that's not a good overall solution for us. What if we want to update other existing maps once we figure it out? or we want to use the same approach with different data we can't fudge as easily...
Thanks for any ideas you've got!
jess