Cooling power steering fluid

I would still need a valve , otherwise the reservoir would overflow. Remember the ps
Is a "closed " system, using a set amount of fluid
I don't think you're hearing what he is saying.

He's saying to run a completely separate cooler for the P/S. It's much simpler, it works, and Ma Mopar did this very thing on a lot of vehicles and in particular on police service vehicles. You can probably still find the factory setup in many junkyards.