Attempt at a combined labelingconfiguration. Overly complex I think.

com.unity.perception/Editor/Unity.Perception.Editor.asmdef

     ],
     "excludePlatforms": [],
     "allowUnsafeCode": false,
-    "overrideReferences": false,
-    "precompiledReferences": [],
+    "overrideReferences": true,
+    "precompiledReferences": [
+        "Newtonsoft.Json.dll"
+    ],
     "autoReferenced": true,
     "defineConstraints": [],
     "versionDefines": [

com.unity.perception/Editor/GroundTruth/LabelingConfigurationImporter.cs

+using System.IO;
+using Newtonsoft.Json.Linq;
+using UnityEditor.Experimental.AssetImporters;
+using UnityEngine;
+using UnityEngine.Perception.GroundTruth;
+
+namespace UnityEditor.Perception.GroundTruth
+{
+    [ScriptedImporter(1, "labelconfig")]
+    public class LabelingConfigurationImporter : ScriptedImporter
+    {
+        public override void OnImportAsset(AssetImportContext ctx)
+        {
+            var text = File.ReadAllText(ctx.assetPath);
+            var jObject = JObject.Parse(text);
+            var config = ScriptableObject.CreateInstance<LabelingConfiguration>();
+            if (jObject["auto-assign-ids"].HasValues)
+                config.AutoAssignIds =  jObject["auto-assign-ids"].Value<bool>();
+
+            if (jObject["starting-index"].HasValues)
+            {
+                var startingLabelId = (StartingLabelId)jObject["starting-index"].Value<int>();
+                config.StartingLabelId = startingLabelId;
+            }
+
+            if (jObject["configs"].HasValues)
+            {
+
+            }
+            ctx.SetMainObject(config);
+        }
+    }
+}

com.unity.perception/Editor/GroundTruth/LabelingConfigurationImporter.cs.meta

+fileFormatVersion: 2
+guid: b0ecdacff7b34c54b2bad5b04e868356
+timeCreated: 1589474006

com.unity.perception/Runtime/GroundTruth/Labeling/LabelingConfiguration2.cs

+using System;
+using System.Collections.Generic;
+using UnityEngine.Serialization;
+
+namespace UnityEngine.Perception.GroundTruth
+{
+    /// <summary>
+    /// A definition for how a <see cref="Labeling"/> should be resolved to a single label and id for ground truth generation.
+    /// </summary>
+    [CreateAssetMenu(fileName = "LabelingConfiguration2", menuName = "Perception/Labeling Configuration 2", order = 1)]
+    public class LabelingConfiguration2 : ScriptableObject
+    {
+        /// <summary>
+        /// Whether the inspector will auto-assign ids based on the id of the first element.
+        /// </summary>
+        public bool AutoAssignIds = true;
+
+        /// <summary>
+        /// Whether the inspector will start label ids at zero or one when <see cref="AutoAssignIds"/> is enabled.
+        /// </summary>
+        public StartingLabelId StartingLabelId = StartingLabelId.One;
+
+        [SerializeField]
+        public List<string> Labels = new List<string>();
+
+        /// <summary>
+        /// A sequence of <see cref="LabelEntry"/> which defines the labels relevant for this configuration and their values.
+        /// </summary>
+        [FormerlySerializedAs("LabelingConfigurations")]
+        [SerializeField]
+        public List<LabelFeature> LabelFeatures = new List<LabelFeature>();
+
+        /// <summary>
+        /// Attempts to find the matching index in <see cref="LabelEntries"/> for the given <see cref="Labeling"/>.
+        /// </summary>
+        /// <remarks>
+        /// The matching index is the first class name in the given Labeling which matches an entry in <see cref="LabelEntries"/>.
+        /// </remarks>
+        /// <param name="labeling">The <see cref="Labeling"/> to match </param>
+        /// <param name="labelEntry">When this method returns, contains the matching <see cref="LabelEntry"/>, or <code>default</code> if no match was found.</param>
+        /// <returns>Returns true if a match was found. False if not.</returns>
+        public bool TryGetMatchingConfigurationEntry(Labeling labeling, out LabelEntry labelEntry)
+        {
+            return TryGetMatchingConfigurationEntry(labeling, out labelEntry, out int _);
+        }
+
+        /// <summary>
+        /// Attempts to find the matching index in <see cref="LabelEntries"/> for the given <see cref="Labeling"/>.
+        /// </summary>
+        /// <remarks>
+        /// The matching index is the first class name in the given Labeling which matches an entry in <see cref="LabelEntries"/>.
+        /// </remarks>
+        /// <param name="labeling">The <see cref="Labeling"/> to match </param>
+        /// <param name="labelEntry">When this method returns, contains the matching <see cref="LabelEntry"/>, or <code>default</code> if no match was found.</param>
+        /// <param name="labelEntryIndex">When this method returns, contains the index of the matching <see cref="LabelEntry"/>, or <code>-1</code> if no match was found.</param>
+        /// <returns>Returns true if a match was found. False if not.</returns>
+        public bool TryGetMatchingConfigurationEntry(Labeling labeling, out LabelEntry labelEntry, out int labelEntryIndex)
+        {
+            foreach (var labelingClass in labeling.labels)
+            {
+                for (var i = 0; i < LabelEntries.Count; i++)
+                {
+                    var entry = LabelEntries[i];
+                    if (string.Equals(entry.label, labelingClass))
+                    {
+                        labelEntry = entry;
+                        labelEntryIndex = i;
+                        return true;
+                    }
+                }
+            }
+
+            labelEntryIndex = -1;
+            labelEntry = default;
+            return false;
+        }
+    }
+
+    /// <summary>
+    /// Structure defining a label configuration for <see cref="LabelingConfiguration"/>.
+    /// </summary>
+    [Serializable]
+    public class LabelFeature
+    {
+        public string key;
+    }
+    [Serializable]
+    public class StringLabelFeature : LabelFeature
+    {
+        public List<string> values;
+    }
+    [Serializable]
+    public class IntLabelFeature : LabelFeature
+    {
+        public List<string> values;
+    }
+    [Serializable]
+    public class ColorLabelFeature : LabelFeature
+    {
+        public List<string> values;
+    }
+}

com.unity.perception/Runtime/GroundTruth/Labeling/LabelingConfiguration2.cs.meta

+fileFormatVersion: 2
+guid: ef6f93cc88964359a505ccc75835fd5a
+timeCreated: 1589581072