I have used the aerosol copper-spray on some applications, and I don't see where it would hurt with the original configuration head gasket.
If anybody is making up multi-layer steel (MLS) hdgskts for our cars, then I believe the recommendation for them is that they be installed clean and dry. MLS type gaskets are beneficial when, for example, you're putting an aluminum head on a cast-iron block (though composite gaskets were used on the 10.5:1 C.R. S-52 BMW engine, they switched to MLS for the 11.5:1 S-54 engines). I usually switch to an MLS in (or cut-ring for high-boost) supercharged BMW engines.
A .050" solid copper spacer was required for my first turbo build, and the recommendation was to spray it with a light coat of copper, even though it was used in conjunction with an MLS head gasket.