Thank you for your reply.
If your server doesn't require a client mod to join and play on it, you can enable the option I've mentioned above ("<no_client_mods>" setting). It will prohibit all client modifications but the server still can have unpacked Core.cpk or server mods.
But some players use automatic collection
Do you mean the "automaton" mod? On an x10 server? I wonder who actually needs this as the inventory gets filled up very quickly and players never need THAT many twigs, stones, grass, etc.
Again, we don't actually see any harm with this mod as it can't do anything that players cannot do themselves by clicking quickly in the game. It's a convenience mod. But I realize that some players may disagree with me, or simply prefer to have peace of mind that no other players are using any mods on their server.
So do you want to add the server and client mod matching
We're not planning to implement this as it will be trivial to hack and will also make the client overall prone to hacking. Our current security approach (when the server forbids client modifications) works in a different way and ensures that the client is running 100% original code without any modifications. There are layers of protection and validation to ensure this. By design, it's not compatible with the idea of supporting any client modifications.
Regards!