Titanium retainers ARE better for heat dissipation, they are also lighter. Light valvetrain is better, and boosted engines run much hotter than NA setups, that's modding 101 right there. The "increased friction" high lift cams create on the valvetrain is minute compared to the super high cylinder pressure created in a boosted engine cylinder, and therefore heat.
99% of NA setups don't need aftermarket retainers, the only thing they'll do for you is up your bling factor.

I may only have 12 posts on this site, but I'm no newb.