If you're finding a lot of people just leaving the knife menu open, why not:

A) Find them and kill them
B) Go look for them and end up getting killed (least the round is over )
C) Why not have a 5-15 second timer on the menu. If a player does not take an action, the vote is automatically set to 2 (Decline knife fight).

Glad we got a full set of rules for all the main servers