Symbology derived from an Arcade expression not permitting template usage in Field Maps

[Anonymous User]

I am developing a field map layer for us to record polygonal progress through a forestry unit. The symbology for the progress layer was complicated enough that it required the use of an Arcade expression to correctly display.  

We have beta-tested the field map and identified a user need to incorporate templates in this layer.  However, when we go to configure the form, template are unable to be added.  The below screenshot is what is displayed:

My user account owns the layer, and I am able to change templates on other layers.  Reading other help articles, it appears that it might not be possible to use templates if the symbology is derived from Arcade.  I am not sure why, as it seems like the template should just ingest the layer's form to allow for default values.  i also cannot configure the default values feature, however, there is a message posted indicating I can't do it.

Here is the Arcade expression I am using:

var type = $feature.Type
var piling = $feature.Piling
var covering = $feature.Covering
var fireline = $feature.Fireline

if (type == "Machine work"){ 
    if ((piling == "Yes" && covering == "Yes" && fireline == "Yes") || piling == "NA" ){ 
      return "Complete Machine Work"}
    else {return "Incomplete Machine Work"}
}

else if (type == "Handwork"){
    if (piling == "Yes" && covering == "Yes" && fireline == "Yes") {
    return "Complete Handwork"}
    else{return "Incomplete Handwork"}
}

else {return "Other"}