Hum. I don't personally have experience with copper head gaskets but I remember they were used on 60s era GMC blower cars.
The hardness of them matters as they seal by crush rather than anything else.
I do know that teflon coated gaskets such as the Felpro are designed with crush rings around the cylinders to hold compression but permit the head and block to expand at different rates and the head literally floats on the block.
That is more important of a concept with aluminum heads on iron blocks.
The older Victor gaskets common on Fords of the 60s were sealing differently and we often needed to scrape remnants of them off of the top of the block. The Felpro's, not so much.
Unless you have crazy cylinder pressures, I don't see the need for copper gaskets or maybe stated differently, the risk (water leaks) of using them.
You don't need more then 95 pounds of torque to seal the gaskets. The fasteners aren't doing the job, the gaskets are. The only thing head studs are treating is paranoia. At some point they are counter productive and distorting the head and block.