Removed the product user mapping stuff, as it falls well out of the scope of this class. That should be taken care of by the platform-specific use cases.

Assets/Scripts/EOSVoiceChat.cs

@@ -8,7 +8,7 @@ using Epic.OnlineServices.RTCAudio;
 using UnityEngine;
 
 /// <summary>
-/// Generic re-usable cross-platform class to provide common voice chat functionality based on the EOS Voice Chat service.
+/// Generic reusable cross-platform class to provide common voice chat functionality based on the EOS Voice Chat service.
 /// This class does not know anything about EOS platform initialization or authentication; it just takes the required
 /// EOS interfaces and exposes a number of game-related voice functions.
 /// </summary>
@@ -20,7 +20,6 @@ public class EOSVoiceChat
     private readonly RTCInterface rtcInterface;
     private readonly RTCAudioInterface audioInterface;
     private readonly Func<ProductUserId> localUserProvider;
-    private readonly IProductUserMapper productUserMapper;
     
     private readonly Dictionary<ProductUserId, ChatUser> chatUsers = new Dictionary<ProductUserId, ChatUser>();
 
@@ -36,13 +35,12 @@ public class EOSVoiceChat
     /// </summary>
     public EOSVoiceChat(
         LobbyInterface lobbyInterface, RTCInterface rtcInterface, RTCAudioInterface audioInterface, 
-        Func<ProductUserId> localUserProvider, IProductUserMapper productUserMapper)
+        Func<ProductUserId> localUserProvider)
     {
         this.lobbyInterface = lobbyInterface;
         this.rtcInterface = rtcInterface;
         this.audioInterface = audioInterface;
         this.localUserProvider = localUserProvider;
-        this.productUserMapper = productUserMapper;
     }
 
     /// <summary>
@@ -115,7 +113,7 @@ public class EOSVoiceChat
                 
                 chatUsers.Clear();
                 SubscribeToRoomNotifications();
-                connectArgs.onCompleted?.Invoke(true);
+                connectArgs.onCompleted?.Invoke(true);  // NOTE: this callback may come too soon, we probably don't have the list of participants populated yet...
                 break;
             case Result.LobbyLobbyAlreadyExists:
                 // This can happen if two clients try to create the same lobby at the same time, a classic race condition.
@@ -146,7 +144,7 @@ public class EOSVoiceChat
                 
                 chatUsers.Clear();
                 SubscribeToRoomNotifications();
-                connectArgs.onCompleted?.Invoke(true);
+                connectArgs.onCompleted?.Invoke(true);  // NOTE: this callback may come too soon, we probably don't have the list of participants populated yet...
                 break;
             default:
                 connectedLobbyId = null;
@@ -218,21 +216,18 @@ public class EOSVoiceChat
     /// Mute or unmute a specific remove player. This can be used to filter out specific players in the chat lobby,
     /// or for manually muting toxic players. 
     /// </summary>
-    public void SetRemoteMuted(string remotePlayerId, bool muted)
+    public void SetRemoteMuted(ProductUserId remoteUser, bool muted)
     {
         if (!IsConnected)
             return;
         
-        productUserMapper.MapPlatformIdToProductUser(remotePlayerId, remoteProductUser =>
-        {
         audioInterface.UpdateReceiving(new UpdateReceivingOptions
         {
             LocalUserId = localUserProvider.Invoke(),
-                ParticipantId = remoteProductUser,
+            ParticipantId = remoteUser,
             RoomName = rtcRoomName,
             AudioEnabled = !muted,
         }, null, data => { });
-        });
     }
     
     /// <summary>
@@ -272,16 +267,13 @@ public class EOSVoiceChat
     }
 
     /// <summary>
-    /// Whether the requested player is currently talking or not.
-    /// This can be either the local player or a remote player. 
+    /// Whether the requested user is currently talking or not.
+    /// This can be either the local player or a remote user. 
     /// </summary>
-    public bool IsPlayerTalking(string playerId)
+    public bool IsUserTalking(ProductUserId user)
     {
-        foreach (var chatUser in chatUsers.Values)
+        if (chatUsers.TryGetValue(user, out var chatUser))
         {
-            if (chatUser.platformPlayerId != playerId)
-                continue;
-            
             return chatUser.audioStatus == RTCAudioStatus.Enabled && chatUser.isSpeaking;
         }
 
@@ -382,7 +374,6 @@ public class EOSVoiceChat
                     return;
 
                 var chatUser = new ChatUser(data.ParticipantId);
-                productUserMapper.MapProductUserToPlatformId(data.ParticipantId, pid => chatUser.platformPlayerId = pid);
                 chatUsers.Add(data.ParticipantId, chatUser);
                 break;
             case RTCParticipantStatus.Left:
@@ -420,7 +411,6 @@ public class EOSVoiceChat
     {
         public readonly ProductUserId productUserId;
         
-        public string platformPlayerId;
         public RTCAudioStatus audioStatus;
         public bool isSpeaking;
 

Assets/Scripts/MagnificentVoiceChat.cs

@@ -126,7 +126,7 @@ public class MagnificentVoiceChat : MonoBehaviour
             ScopeFlags = AuthScopeFlags.BasicProfile,
         }, null, HandleLoginResult);
 
-        voiceChat = new EOSVoiceChat(lobbyInterface, rtcInterface, audioInterface, () => localProductUserId, new NilProductUserMapper());
+        voiceChat = new EOSVoiceChat(lobbyInterface, rtcInterface, audioInterface, () => localProductUserId);
     }
 
     private Credentials GetEpicCredentials()    // This is platform-specific
@@ -305,15 +305,4 @@ public class MagnificentVoiceChat : MonoBehaviour
         
         GUILayout.Label(status.ToString());
     }
-
-    private class NilProductUserMapper : IProductUserMapper
-    {
-        public void MapProductUserToPlatformId(ProductUserId productUserId, Action<string> platformIdCallback)
-        {
-        }
-
-        public void MapPlatformIdToProductUser(string platformId, Action<ProductUserId> productUserCallback)
-        {
-        }
-    }
 }