The idea i have described here fix the multiplayer mods compatibility issue by :
_Give more control from server side user to which mods he want or not in the server.
_More strict but without restriction for player side check for mods that can permit to having more control over cheater/illegal game modification.
_"Reloading" before server possibility permit to disabled/enable mods and by the same way to work after a download get new mods for match with server without need to restart and deal with long and boring disabled of mods and game full restart, probably one of the major factor that make a lot of server to be empty, people launch a game for play it and not for deal/fight against mods management for EACH server, consume more time before connection cause of the reloading when mods don't match.
_Different mods for multiplayer and singleplayer that permit to customize the singleplayer how we want without have to load it for multiplayer, useful for some huge gameplay modification that was mainly/only created for singleplayer or multiplayer.
_Mods website/server that permit to have a lot of information for each mods for server creator and permit to download mods before entering in the server or download the small size object version without influencing server band switch/connection stability/latency.
_No issue with constant needed internet connection, it only need it for download mods/small lod variant or for the server creator to access to live mods list/information for allowing it or not, anyway for player in multiplayer we need internet connection.