diff --git a/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/Cell.cs b/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/Cell.cs
index 684f04854f..9d11d4fc9c 100644
--- a/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/Cell.cs
+++ b/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/Cell.cs
@@ -1,11 +1,14 @@
-using System.Collections.Generic;
+using System;
+using System.Diagnostics;
+
+using BizHawk.Common;
 
 namespace BizHawk.Client.EmuHawk
 {
 	/// <summary>
 	/// Represents a single cell of the <see cref="InputRoll"/>
 	/// </summary>
-	public class Cell
+	public sealed class Cell : IComparable<Cell>
 	{
 		public RollColumn Column { get; internal set; }
 		public int? RowIndex { get; internal set; }
@@ -19,6 +22,9 @@ namespace BizHawk.Client.EmuHawk
 			RowIndex = cell.RowIndex;
 		}
 
+		public int CompareTo(Cell other)
+			=> SortCell.Compare(this, other);
+
 		public override bool Equals(object obj)
 		{
 			if (obj is Cell cell)
@@ -45,9 +51,9 @@ namespace BizHawk.Client.EmuHawk
 		}
 	}
 
-	internal class SortCell : IComparer<Cell>
+	internal static class SortCell
 	{
-		int IComparer<Cell>.Compare(Cell c1, Cell c2)
+		public static int Compare(Cell c1, Cell c2)
 		{
 			if (c1 is null && c2 is null)
 			{
@@ -86,6 +92,21 @@ namespace BizHawk.Client.EmuHawk
 		}
 	}
 
+	public sealed class CellList : SortedList<Cell>
+	{
+		/// <remarks>restore the distinctness invariant from <see cref="System.Collections.Generic.SortedSet{T}"/>; though I don't think we actually rely on it anywhere --yoshi</remarks>
+		public override void Add(Cell item)
+		{
+			var i = _list.BinarySearch(item);
+			if (i >= 0)
+			{
+				Debug.Assert(false, $"{nameof(CellList)}'s distinctness invariant was almost broken! CellList.Add({(item is null ? "null" : $"Cell(r: {item.RowIndex}, c: \"{item.Column?.Name ?? "(unnamed)"}\")")})");
+				return;
+			}
+			_list.Insert(~i, item);
+		}
+	}
+
 	public static class CellExtensions
 	{
 		public static bool IsDataCell(this Cell cell)
diff --git a/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs b/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs
index f9ac41b797..2ef5e99ae9 100644
--- a/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs
+++ b/src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs
@@ -22,7 +22,8 @@ namespace BizHawk.Client.EmuHawk
 	public partial class InputRoll : Control
 	{
 		private readonly IControlRenderer _renderer;
-		private readonly SortedSet<Cell> _selectedItems = new SortedSet<Cell>(new SortCell());
+
+		private readonly CellList _selectedItems = new();
 
 		// scrollbar location(s) are calculated later (e.g. on resize)
 		private readonly VScrollBar _vBar = new VScrollBar { Visible = false };
@@ -265,13 +266,10 @@ namespace BizHawk.Client.EmuHawk
 
 					_rowCount = value;
 
+					//TODO replace this with a binary search + truncate
 					if (_selectedItems.Max(s => s.RowIndex) >= _rowCount)
 					{
-#if NETFRAMEWORK
 						_selectedItems.RemoveAll(i => i.RowIndex >= _rowCount);
-#else
-						_selectedItems.RemoveWhere(i => i.RowIndex >= _rowCount);
-#endif
 					}
 
 					RecalculateScrollBars();
@@ -576,7 +574,8 @@ namespace BizHawk.Client.EmuHawk
 				}
 				else
 				{
-					_selectedItems.RemoveWhere(cell => cell.RowIndex == index);
+					IEnumerable<Cell> items = _selectedItems.Where(cell => cell.RowIndex == index);
+					_selectedItems.RemoveAll(items.Contains);
 					_lastSelectedRow = _selectedItems.LastOrDefault()?.RowIndex;
 				}
 			}
@@ -612,7 +611,7 @@ namespace BizHawk.Client.EmuHawk
 
 		public void TruncateSelection(int index)
 		{
-			_selectedItems.RemoveWhere(cell => cell.RowIndex > index);
+			_selectedItems.RemoveAll(cell => cell.RowIndex > index);
 			_lastSelectedRow = _selectedItems.LastOrDefault()?.RowIndex;
 		}
 
@@ -1788,7 +1787,7 @@ namespace BizHawk.Client.EmuHawk
 
 				if (FullRowSelect)
 				{
-					if (toggle && (_selectedItems.RemoveWhere(x => x.RowIndex == row) is not 0))
+					if (toggle && (_selectedItems.RemoveAll(x => x.RowIndex == row) is not 0))
 					{
 						_lastSelectedRow = _selectedItems.LastOrDefault()?.RowIndex;
 					}