Question Getting Custom Player data at server start

Hello all,

I have been using multiplay and matchmaker to test a multiplayer game, I need to send in the game custom items that the player equips in a lobby, I have been adding that data here :
ClientSingleton.Instance.Manager.User.Data
but there is a limit to this, somewhere around 1024 bytes before you will get a connection refusal because they payload is too big. Is there an alternate way to pass in custom data or should I just focus on better serialization and data minimization. The items are all stored in the Economy system, so maybe I could just stored their ids and then pull them from the economy once the character is loaded in?