Trying to change the default value through the REST API throws this error:
[ { "type": "ObjectValidationError", "container": { "type": "ObjectKey", "container": { "type": "ObjectKey", "objectId": "64", "objectType": "Form" }, "objectId": "10245", "objectType": "FormField" }, "property": "defaultValue", "requirement": { "type": "StringLengthRequirement", "maxLength": 100 }, "value": "......" } ]