When syncing to do Eureka and Bozja content, I've heard some people say that the way the syncing works you get better results if you use an actual level 70 or 80 weapon (respectively) with materia of the appropriate level for that weapon, as compared to just wearing your level 90 gear and materia and letting the syncing scale it down. Is there any truth to that?

To be clear, I know there are special Eureka-specific items like the Vermillion Cloak that give boosts when in Eureka, those aren't what I'm asking about.