Why is this Property Value Converter still having Umbraco v8.3.0 ModelsBuilder output type of 'object' rather than 'bool'

Controller.js

angular.module('umbraco').directive('switch', function () {
    return {
        restrict: 'AE',
        replace: true,
        transclude: true,
        template: function (element, attrs) {
            var html = '';
            html += '<span';
            html += ' class="switcher' + (attrs.class ? ' ' + attrs.class : '') + '"';
            html += attrs.ngModel ? ' ng-click="' + attrs.ngModel + '=!' + attrs.ngModel + '"' : '';
            html += ' ng-class="{ checked:' + attrs.ngModel + ' }"';
            html += '>';
            html += '<small></small>';
            html += '<input type="checkbox"';
            html += attrs.id ? ' id="' + attrs.id + '-check"' : '';
            html += attrs.name ? ' name="' + attrs.name + '"' : '';
            html += attrs.ngModel ? ' ng-model="' + attrs.ngModel + '"' : '';
            html += ' style="display:none" />';
            html += '</span>';
            return html;
        }
    }
});

angular.module("umbraco").controller("ESO.TrueFalse.Controller", function ($scope, $timeout, angularHelper) {

    var alreadyDirty = false;

    $scope.model.textRight = "";

    if ($scope.model.value === null || $scope.model.value === "") {
        $scope.enabled = 0;
    } else {
        $scope.enabled = $scope.model.value == 1;
    }

    $scope.$watch('enabled', function (newval, oldval) {

        $scope.model.value = newval === true ? 1 : 0;

        if ($scope.model.value == 1) {
            $scope.model.textRight = "Yes";

        }
        else {
            $scope.model.textRight = "No";
        }

        if (newval !== oldval) {
            //run after DOM is loaded
            $timeout(function () {
                if (!alreadyDirty) {
                    var currForm = angularHelper.getCurrentForm($scope);
                    currForm.$setDirty();
                    alreadyDirty = true;
                }
            }, 0);
        }

    }, true);

});

output.cs

//------------------------------------------------------------------------------
// <auto-generated>
//   This code was generated by a tool.
//
//    Umbraco.ModelsBuilder v8.1.0
//
//   Changes to this file will be lost if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using System.Web;
using Umbraco.Core.Models;
using Umbraco.Core.Models.PublishedContent;
using Umbraco.Web;
using Umbraco.ModelsBuilder;
using Umbraco.ModelsBuilder.Umbraco;


/// <summary>Global Settings</summary>
[PublishedModel("globalSettings")]
public partial class GlobalSettings : PublishedContentModel
{

  ...

  ///<summary>
  /// Enable
  ///</summary>
  [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Umbraco.ModelsBuilder", "8.1.0")]
  [ImplementPropertyType("enable")]
  public object Enable => this.Value("enable");
  ...
}

Screenshot.txt

Picture of Data Type, pointing at the Property Editor

https://pasteboard.co/IJZsSoM.png 

TrueFalseValueConverter.cs

using Umbraco.Core;
using Umbraco.Core.Models;
using Umbraco.Core.Models.PublishedContent;
using Umbraco.Core.PropertyEditors;
using Umbraco.Web;
using System;


public class TrueFalseValueConverter : Umbraco.Core.PropertyEditors.PropertyValueConverterBase
{
    public override bool IsConverter(IPublishedPropertyType propertyType) => propertyType.EditorAlias.Equals("ESO.TrueFalse", StringComparison.InvariantCultureIgnoreCase);

    public virtual object ConvertDataToSource(PublishedPropertyType propertyType, object source, bool preview)
    {
          var attemptConvertInt = source.TryConvertTo<bool>();
            if (attemptConvertInt.Success)
            {
                return attemptConvertInt.Result;
            }

            return null;
    }

    public virtual object ConvertSourceToXPath(
      PublishedPropertyType propertyType,
      object source,
      bool preview)
    {
        if (!(bool)source)
            return (object) source.ToString();
        return (object) false;
    }
}

View.html

<div ng-controller="ESO.TrueFalse.Controller" class="usn-cms">
    <switch name="enabled" ng-model="enabled" id="{{model.alias}}"></switch>
    <span class="switcher-status" ng-class="{ active: enabled }">{{model.textRight}}</span>
</div>

Turns out it was missing a method

public override Type GetPropertyValueType(IPublishedPropertyType propertyType) => typeof(bool);

Is there an interface we could tie this up with? That would prevent this sort of thing happening to future unsuspecting developers