Only works at Solo/Non-competitive Environments, like Chapters, Stockvault, Dragon Raids, Labyrinth and I'm not sure, but works in Eclipse for some waves.
Basically, in these Coop/Competitive Environments we need to have very well built characters to play without the mod functions and grow even more.
Probably data from client-side need match to server-side, because they need it for ranking/recording or something like that.