Move cloning local to editor

osu.Game/Beatmaps/WorkingBeatmap.cs

@@ -111,8 +111,6 @@ public IBeatmap GetPlayableBeatmap(RulesetInfo ruleset, IReadOnlyList<Mod> mods
                 // Convert
                 IBeatmap converted = converter.Convert(cancellationSource.Token);
 
-                converted.ControlPointInfo = converted.ControlPointInfo.CreateCopy();
-
                 // Apply conversion mods to the result
                 foreach (var mod in mods.OfType<IApplicableAfterBeatmapConversion>())
                 {

osu.Game/Screens/Edit/Editor.cs

@@ -131,6 +131,10 @@ private void load(OsuColour colours, GameHost host, OsuConfigManager config)
             try
             {
                 playableBeatmap = Beatmap.Value.GetPlayableBeatmap(Beatmap.Value.BeatmapInfo.Ruleset);
+
+                // clone these locally for now to avoid incurring overhead on GetPlayableBeatmap usages.
+                // eventually we will want to improve how/where this is done as there are issues with *not* cloning it in all cases.
+                playableBeatmap.ControlPointInfo = playableBeatmap.ControlPointInfo.CreateCopy();
             }
             catch (Exception e)
             {