diff --git a/PKHeX.Core/Saves/SAV3XD.cs b/PKHeX.Core/Saves/SAV3XD.cs
index 9e00dea66..b9317db4a 100644
--- a/PKHeX.Core/Saves/SAV3XD.cs
+++ b/PKHeX.Core/Saves/SAV3XD.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace PKHeX.Core
 {
@@ -198,8 +197,8 @@ public override string ChecksumInfo
                 int newHC = BigEndian.ToInt32(data, start + subOffsets[0] + 0x38);
                 bool header = newHC == oldHC;
 
-                var oldCHK = Data.Skip(0x10).Take(0x10);
-                var newCHK = data.Skip(0x10).Take(0x10);
+                var oldCHK = Data.AsSpan(0x10, 0x10);
+                var newCHK = data.AsSpan(0x10, 0x10);
                 bool body = newCHK.SequenceEqual(oldCHK);
                 return $"Header Checksum {(header ? "V" : "Inv")}alid, Body Checksum {(body ? "V" : "Inv")}alid.";
             }
@@ -221,13 +220,17 @@ private static byte[] SetChecksums(byte[] input, int subOffset0)
             BigEndian.GetBytes(newHC).CopyTo(data, start + subOffset0 + 0x38);
 
             // Body Checksum
-            new byte[16].CopyTo(data, 0x10); // Clear old Checksum Data
+            data.AsSpan(0x10, 0x10).Fill(0); // Clear old Checksum Data
             uint[] checksum = new uint[4];
             int dt = 8;
-            for (int i = 0; i < 4; i++)
+            for (int i = 0; i < checksum.Length; i++)
             {
-                for (int j = 0; j < 0x9FF4; j += 2, dt += 2)
-                    checksum[i] += BigEndian.ToUInt16(data, dt);
+                uint val = 0;
+                var end = dt + 0x9FF4;
+                for (int j = dt; j < end; j += 2)
+                    val += BigEndian.ToUInt16(data, j);
+                dt = end;
+                checksum[i] = val;
             }
 
             ushort[] newchks = new ushort[8];
diff --git a/PKHeX.Core/Saves/Substructures/Gen7/PokeListHeader.cs b/PKHeX.Core/Saves/Substructures/Gen7/PokeListHeader.cs
index f116bf555..7871717c2 100644
--- a/PKHeX.Core/Saves/Substructures/Gen7/PokeListHeader.cs
+++ b/PKHeX.Core/Saves/Substructures/Gen7/PokeListHeader.cs
@@ -29,13 +29,20 @@ public sealed class PokeListHeader : SaveBlock
         public PokeListHeader(SAV7b sav, int offset) : base(sav)
         {
             Offset = offset;
-            PokeListInfo = LoadPointerData();
+            var info = PokeListInfo = LoadPointerData();
             if (!sav.State.Exportable)
             {
                 for (int i = 0; i < COUNT; i++)
-                    PokeListInfo[i] = SLOT_EMPTY;
+                    info[i] = SLOT_EMPTY;
+            }
+            else
+            {
+                for (int i = 0; i < 6; i++)
+                {
+                    if (info[i] < MAX_SLOTS)
+                        ++_partyCount;
+                }
             }
-            PartyCount = PokeListInfo.Take(6).Count(z => z < MAX_SLOTS);
         }
 
         private int _partyCount;
diff --git a/PKHeX.WinForms/Controls/PKM Editor/StatEditor.cs b/PKHeX.WinForms/Controls/PKM Editor/StatEditor.cs
index ac82d4a20..5c086d9d1 100644
--- a/PKHeX.WinForms/Controls/PKM Editor/StatEditor.cs	
+++ b/PKHeX.WinForms/Controls/PKM Editor/StatEditor.cs	
@@ -552,7 +552,7 @@ public void InitializeDataSources()
         {
             ChangingFields = true;
             CB_HPType.InitializeBinding();
-            CB_HPType.DataSource = Util.GetCBList(GameInfo.Strings.types.Skip(1).Take(16).ToArray());
+            CB_HPType.DataSource = Util.GetCBList(GameInfo.Strings.types.AsSpan(1, 16));
             ChangingFields = false;
         }
 
diff --git a/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_BoxLayout.cs b/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_BoxLayout.cs
index ddc2f1092..8b39e09f4 100644
--- a/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_BoxLayout.cs	
+++ b/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_BoxLayout.cs	
@@ -43,13 +43,13 @@ private bool LoadWallpaperNames()
             switch (SAV.Generation)
             {
                 case 3 when SAV is SAV3:
-                    CB_BG.Items.AddRange(GameInfo.Strings.wallpapernames.Take(16).ToArray());
+                    CB_BG.Items.AddRange(GameInfo.Strings.wallpapernames.Slice(0, 16));
                     return true;
                 case 4 or 5 or 6:
                     CB_BG.Items.AddRange(GameInfo.Strings.wallpapernames);
                     return true;
                 case 7:
-                    CB_BG.Items.AddRange(GameInfo.Strings.wallpapernames.Take(16).ToArray());
+                    CB_BG.Items.AddRange(GameInfo.Strings.wallpapernames.Slice(0, 16));
                     return true;
                 case 8:
                     CB_BG.Items.AddRange(Enumerable.Range(1, 19).Select(z => $"Wallpaper {z}").ToArray());
diff --git a/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_HallOfFame.cs b/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_HallOfFame.cs
index 8d3de2eb6..08c93108a 100644
--- a/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_HallOfFame.cs	
+++ b/PKHeX.WinForms/Subforms/Save Editors/Gen6/SAV_HallOfFame.cs	
@@ -419,7 +419,7 @@ private void ChangeNickname(object sender, MouseEventArgs e)
                 return;
 
             int offset = LB_DataEntry.SelectedIndex * 0x1B4;
-            var nicktrash = data.Skip(offset + 0x18).Take(24).ToArray();
+            var nicktrash = data.Slice(offset + 0x18, 24);
             SAV.SetString(TB_Nickname.Text, 12).CopyTo(nicktrash, 0);
             var d = new TrashEditor(tb, nicktrash, SAV);
             d.ShowDialog();
diff --git a/PKHeX.WinForms/Subforms/Save Editors/Gen7/SAV_ZygardeCell.cs b/PKHeX.WinForms/Subforms/Save Editors/Gen7/SAV_ZygardeCell.cs
index db57263b1..f06abc56e 100644
--- a/PKHeX.WinForms/Subforms/Save Editors/Gen7/SAV_ZygardeCell.cs	
+++ b/PKHeX.WinForms/Subforms/Save Editors/Gen7/SAV_ZygardeCell.cs	
@@ -1,5 +1,4 @@
 using System;
-using System.Linq;
 using System.Windows.Forms;
 using PKHeX.Core;
 
@@ -20,7 +19,7 @@ public SAV_ZygardeCell(SaveFile sav)
             // Cell Data @ 0x1D8C
             // Use constants 0x18C/2 = 198 thru +95
             ushort[] constants = SAV.GetEventConsts();
-            ushort[] cells = constants.Skip(celloffset).Take(CellCount).ToArray();
+            ushort[] cells = constants.Slice(celloffset, CellCount);
 
             int cellCount = constants[cellstotal];
             int cellCollected = constants[cellscollected];