Your thinking it's a clutch itself and it isn't. Read the paragraph below it's straight from Direct Drives website and will answer your questions.
A lockout is designed to do two things, (1) eliminate excessive clutch slippage to facilitate the transfer
of as much horsepower to the rear tires as possible and (2) make the bike quicker. Many people install
a lockout only for the purpose of keeping the clutch from slipping, but if you are willing to do some
experimenting with spring pressure and lockout weight, in many instances you can make the bike
quicker. There are many different rider,engine,bike and weight combinations, do what works best for
your specific setup and not what the current lucky guy setup is. His setup may be completely wrong for
your bike .Best case scenario is to Set your clutch up to work as a 2 stage clutch, some slippage out of
the hole then Lockup the clutch as early as possible.
The spring pressure regulates how hard that the bike leaves from the start.
If the spring pressure is to stiff it can cause excessive tire spin. If the springs are to soft it can cause
excessive clutch slippage. By setting up your clutch to have a small amount of slippage off the line you
will keep the rpm