One-Click migrates all supported baked lights on scene to use Bakery.

BakeryAutoMigrate.cs

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.SceneManagement;
using UnityEditor;

public static class BakeryAutoMigrate {
    static Texture2D spotCookie;

    [MenuItem("Bakery/Utilities/Migrate and Adjust Lights", priority = 60)]
    public static void AuoMigrate() {
        var queue = new Queue<Transform>();
        var temp = new List<GameObject>();
        for (int i = 0, count = SceneManager.loadedSceneCount; i < count; i++) {
            var scene = SceneManager.GetSceneAt(i);
            scene.GetRootGameObjects(temp);
            foreach (var go in temp) queue.Enqueue(go.transform);
        }
        int counter = 0;
        while (queue.TryDequeue(out var transform)) {
            for (int i = 0, count = transform.childCount; i < count; i++) {
                var child = transform.GetChild(i);
                queue.Enqueue(child);
            }
            if (!transform.TryGetComponent(out Light light) ||
                light.lightmapBakeType == LightmapBakeType.Realtime) continue;
            BakeryPointLight pointLight;
            BakeryDirectLight directLight;
            BakeryLightMesh lightMesh;
            switch (light.type) {
                case LightType.Point:
                case LightType.Spot:
                    if (light.TryGetComponent(out directLight)) Undo.DestroyObjectImmediate(directLight);
                    if (light.TryGetComponent(out lightMesh)) Undo.DestroyObjectImmediate(lightMesh);
                    if (!light.TryGetComponent(out pointLight))
                        pointLight = Undo.AddComponent<BakeryPointLight>(light.gameObject);
                    else
                        Undo.RecordObject(pointLight, "Bakery Migrator");
                    GetLinearLightParameters(light, out pointLight.color, out pointLight.intensity);
                    pointLight.indirectIntensity = light.bounceIntensity;
                    pointLight.cutoff = light.range;
                    pointLight.angle = light.spotAngle;
                    if (light.type == LightType.Spot) {
                        pointLight.cookie = light.cookie as Texture2D;
                        if (!pointLight.cookie) {
                            if (!spotCookie) spotCookie = AssetDatabase.LoadAssetAtPath<Texture2D>($"{ftLightmaps.GetRuntimePath()}ftUnitySpotTexture.bmp");
                            pointLight.cookie = spotCookie;
                        }
                        pointLight.projMode = BakeryPointLight.ftLightProjectionMode.Cookie;
                    } else {
                        pointLight.cookie = light.cookie as Texture2D;
                        pointLight.projMode = pointLight.cookie ?
                            BakeryPointLight.ftLightProjectionMode.Cubemap :
                            BakeryPointLight.ftLightProjectionMode.Omni;
                    }
                    counter++;
                    break;
                case LightType.Directional:
                    if (light.TryGetComponent(out lightMesh)) Undo.DestroyObjectImmediate(lightMesh);
                    if (light.TryGetComponent(out pointLight)) Undo.DestroyObjectImmediate(pointLight);
                    if (!light.TryGetComponent(out directLight))
                        directLight = Undo.AddComponent<BakeryDirectLight>(light.gameObject);
                    else
                        Undo.RecordObject(directLight, "Bakery Migrator");
                    GetLinearLightParameters(light, out directLight.color, out directLight.intensity);
                    directLight.indirectIntensity = light.bounceIntensity;
                    counter++;
                    break;
                case LightType.Rectangle:
                    if (light.TryGetComponent(out directLight)) Undo.DestroyObjectImmediate(directLight);
                    if (light.TryGetComponent(out pointLight)) Undo.DestroyObjectImmediate(pointLight);
                    if (!light.TryGetComponent(out lightMesh))
                        lightMesh = Undo.AddComponent<BakeryLightMesh>(light.gameObject);
                    else
                        Undo.RecordObject(lightMesh, "Bakery Migrator");
                    GetLinearLightParameters(light, out lightMesh.color, out lightMesh.intensity);
                    lightMesh.indirectIntensity = light.bounceIntensity;
                    lightMesh.cutoff = light.range * 1.5F;
                    lightMesh.selfShadow = false;
                    counter++;
                    break;
                default:
                    Debug.LogWarning($"Unsupported light type: {light.type}", light);
                    break;
            }
        }
        if (counter > 0) {
            Undo.CollapseUndoOperations(Undo.GetCurrentGroup());
            EditorUtility.DisplayDialog("Bakery Migrator", $"Migrated and adjusted {counter} lights.", "OK");
        }
    }

    static void GetLinearLightParameters(Light light, out Color lightColor, out float intensity) {
        intensity = light.intensity;
        lightColor = light.color;
        if (PlayerSettings.colorSpace != ColorSpace.Linear) return;
        if (!GraphicsSettings.lightsUseLinearIntensity) {
            lightColor.r = Mathf.Pow(lightColor.r * intensity, 2.2f);
            lightColor.g = Mathf.Pow(lightColor.g * intensity, 2.2f);
            lightColor.b = Mathf.Pow(lightColor.b * intensity, 2.2f);
            intensity = Mathf.Max(Mathf.Max(lightColor.r, lightColor.g), lightColor.b);
            lightColor /= intensity;
        } else if (GraphicsSettings.lightsUseColorTemperature) {
#if UNITY_2019_3_OR_NEWER
            if (!light.useColorTemperature) return;
#endif
            lightColor *= Mathf.CorrelatedColorTemperatureToRGB(light.colorTemperature).gamma;
        }
        lightColor.a = 1;
    }
}