Theres no way to detect a net lagger in lobby atm, so heres solution.
And foelist is useless if you are playing in not your own lobby.
Hosts can blacklist people who lags very hard and non-stop to no longer allow them at their games.
Everyone other is able to see how many people blacklisted this guy in lobby, and decide to allow him to play or not.
If someone blacklists people masses (just to grief) disable his ability to blacklist.
I think enough info.
Or a kick option to kick hard-lagging players if they dont quit themselves.