@iamnithesh’s suggestion is bang on! I think this is what you need instead based on what he suggested:
{
"name": "Lifecycle State - Emergency Exit",
"type": "static",
"attributes": {
"emergencyExitValue": {
"type": "firstValid",
"attributes": {
"values": [
{
"attributes": {
"sourceName": "Duplicate Source - Testing",
"attributeName": "emergencyExitFlag"
},
"type": "accountAttribute"
},
"none"
],
"ignoreErrors": true
}
},
"value": "#if($emergencyExitValue == 'true')Emergency Exit#else null#end"
},
"internal": false
}