Mando,
I'd seal the other valve cover or run a line from each cover. The PCV valve is a 1 way check valve that's designed to promote a vacuum in your crank case. At part throttle when manifold vacuum is high it pulls from the crank case also creating negative pressure in there. When you put your boot down your manifold vacuum drops off but the PCV check valve closes keeping the crank case vacuum up.
All engines have a certain amount of blow-by where combustion pressure leaks down past the rings and into the crank case. It can also sneak out through the valve guides. The main reason for the PCV is it stops the crank case pressurizing and forcing
oil out through your crank seals and other places. Crank case vacuum also promotes ring seal as the rings are pushed out against the cylinder wall by the combustion pressure. Crank case pressure works against this pressure.
It's been popular in drag racing to use a mechanical engine driven vacuum pump to generate high levels of crank case vacuum. The power used to drive the pump is more than made up by the extra power made by good ring seal.
Mine is just vented to atmosphere that creates the need for large diameter lines for max airflow. There's a school of thought that says burning that
oil vapor actually drops the octane rating of your fuel. It may not be legal for rego but I rould rather catch and condense the
oil vapor and return it to the motor than burn it.
Cheers