diff --git a/ApplicationServices/LibraryCommands.cs b/ApplicationServices/LibraryCommands.cs
index 2c438d2a..7fd373b1 100644
--- a/ApplicationServices/LibraryCommands.cs
+++ b/ApplicationServices/LibraryCommands.cs
@@ -67,7 +67,7 @@ namespace ApplicationServices
 
 		static System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
 		record timeLogEntry(string msg, long totalElapsed, long delta);
-		static List<timeLogEntry> __log { get; } = new List<timeLogEntry> { new("begin", 0, 0) };
+		static List<timeLogEntry> __log { get; } = new List<timeLogEntry>();
 		static void logTime(string s)
 		{
 			var totalElapsed = sw.ElapsedMilliseconds;
@@ -81,7 +81,9 @@ namespace ApplicationServices
 		#region FULL LIBRARY scan and import
 		public static async Task<(int totalCount, int newCount)> ImportAccountAsync(Func<Account, ILoginCallback> loginCallbackFactoryFunc, params Account[] accounts)
 		{
-			sw.Start();
+			__log.Clear();
+			__log.Add(new("begin", 0, 0));
+			sw.Restart();
 
 			if (accounts is null || accounts.Length == 0)
 				return (0, 0);
diff --git a/DataLayer/EfClasses/Book.cs b/DataLayer/EfClasses/Book.cs
index 4334023d..8f2d85c1 100644
--- a/DataLayer/EfClasses/Book.cs
+++ b/DataLayer/EfClasses/Book.cs
@@ -30,8 +30,6 @@ namespace DataLayer
         public string Description { get; private set; }
         public int LengthInMinutes { get; private set; }
         public ContentType ContentType { get; private set; }
-
-        // immutable-ish. should be immutable. mutability is necessary for v3 => v4 upgrades
         public string Locale { get; private set; }
 
         // mutable
@@ -78,7 +76,8 @@ namespace DataLayer
             ContentType contentType,
 			IEnumerable<Contributor> authors,
 			IEnumerable<Contributor> narrators,
-			Category category, string localeName)
+			Category category,
+            string localeName)
         {
             // validate
             ArgumentValidator.EnsureNotNull(audibleProductId, nameof(audibleProductId));
@@ -260,10 +259,6 @@ namespace DataLayer
 			Category = category;
         }
 
-        // needed for v3 => v4 upgrade
-        public void UpdateLocale(string localeName)
-            => Locale ??= localeName;
-
         public override string ToString() => $"[{AudibleProductId}] {Title}";
 	}
 }
diff --git a/DataLayer/EfClasses/LibraryBook.cs b/DataLayer/EfClasses/LibraryBook.cs
index e58e3929..45f9f584 100644
--- a/DataLayer/EfClasses/LibraryBook.cs
+++ b/DataLayer/EfClasses/LibraryBook.cs
@@ -9,8 +9,6 @@ namespace DataLayer
         public Book Book { get; private set; }
 
         public DateTime DateAdded { get; private set; }
-
-        // immutable-ish. should be immutable. mutability is necessary for v3 => v4 upgrades
         public string Account { get; private set; }
 
         private LibraryBook() { }
@@ -24,10 +22,6 @@ namespace DataLayer
             Account = account;
         }
 
-        // needed for v3 => v4 upgrade
-        public void UpdateAccount(string account)
-            => Account ??= account;
-
         public override string ToString() => $"{DateAdded:d} {Book}";
 	}
 }
diff --git a/DtoImporterService/BookImporter.cs b/DtoImporterService/BookImporter.cs
index bb0a874f..6e7b96a1 100644
--- a/DtoImporterService/BookImporter.cs
+++ b/DtoImporterService/BookImporter.cs
@@ -155,9 +155,6 @@ namespace DtoImporterService
 			book.PictureId = item.PictureId;
 			book.UpdateProductRating(item.Product_OverallStars, item.Product_PerformanceStars, item.Product_StoryStars);
 
-			// needed during v3 => v4 migration
-			book.UpdateLocale(importItem.LocaleName);
-
 			// important to update user-specific info. this will have changed if user has rated/reviewed the book since last library import
 			book.UserDefinedItem.UpdateRating(item.MyUserRating_Overall, item.MyUserRating_Performance, item.MyUserRating_Story);
 
diff --git a/DtoImporterService/LibraryBookImporter.cs b/DtoImporterService/LibraryBookImporter.cs
index b416db4c..673a1988 100644
--- a/DtoImporterService/LibraryBookImporter.cs
+++ b/DtoImporterService/LibraryBookImporter.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using AudibleApi.Common;
 using DataLayer;
 using InternalUtilities;
 
@@ -28,7 +27,8 @@ namespace DtoImporterService
 			// - what to show in the grid
 			// - which to consider liberated
 			//
-			// sqlite cannot alter pk. the work around is an extensive headache. it'll be fixed in pre .net5/efcore5
+			// sqlite cannot alter pk. the work around is an extensive headache
+			// - update: now possible in .net5/efcore5
 			//
 			// currently, inserting LibraryBook will throw error if the same book is in multiple accounts for the same region.
 			//
@@ -46,15 +46,6 @@ namespace DtoImporterService
 				DbContext.LibraryBooks.Add(libraryBook);
 			}
 
-			// needed for v3 => v4 upgrade
-			var toUpdate = DbContext.LibraryBooks.Where(l => l.Account == null);
-			foreach (var u in toUpdate)
-			{
-				var item = importItems.FirstOrDefault(ii => ii.DtoItem.ProductId == u.Book.AudibleProductId);
-				if (item != null)
-					u.UpdateAccount(item.AccountId);
-			}
-
 			var qtyNew = newItems.Count;
 			return qtyNew;
 		}
diff --git a/LibationLauncher/LibationLauncher.csproj b/LibationLauncher/LibationLauncher.csproj
index 675b4d8d..9213d30f 100644
--- a/LibationLauncher/LibationLauncher.csproj
+++ b/LibationLauncher/LibationLauncher.csproj
@@ -13,7 +13,7 @@
     <!-- <PublishSingleFile>true</PublishSingleFile> -->
     <RuntimeIdentifier>win-x64</RuntimeIdentifier>
 
-    <Version>5.6.3.6</Version>
+    <Version>5.6.3.10</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">