From the documentation:

Ursprungligen skrivet av Documentation:

It works by reading which player is the "host" in the frontend. That player's mct_settings.lua file is read on the initial load of the campaign, and the settings decided are sent to the client player to keep everything matched. From then on, only the host can edit settings in the MCT dialogues, and the client can only read the settings; the only exception being local-only settings, which aren't sent through to both players. The host and the client can both have different settings for a local-only setting.

Be very careful with local-only settings. This should be done for very simple stuff that won't cause desyncs - UI settings, script logging, stuff like that.

So basically it is set by the host. But there are settings (local) that may be not syncronized. And if a modder does not care about this, it may lead to desync. So I think to be safe it is still saver to manually have the same settings on all clients.

For that you can copy and share the mct_registry.lua file in "%appdata%\The Creative Assembly\Warhammer3\scripts"

thanks mate

I have a problem with chaos robbie old world map where the start positions for elftown does not change in multiplayer even if i go into the mct_registry.lua and change the default_value it just changes back when i start the game

is there a way to lock the setting so it takes effect in multiplayer lobbies