Compatibility options are not enforced to clients by servers
You can join a server and change your local compatibility settings while in a server. An example is to join a server that has co_realactorheight enabled, and then go into your compatibility menu and change "Items can be walked over/under" to off. You will still go through things (like bridge things) but the client will jerk back and forth as if it is fighting the server.
An improvement would be to check whether the player has rcon privileges before toggling any of these options. Otherwise, the player doesn't have the right to locally modify these in multiplayer.