"For foreign currency holders precious metals would get more attractive"

Absolutely. The end game is there. US dollar supply will double/triple from here on in an effort to export the most of 50 years of accumulated deficit to the rest of the world.

The Russians knew it, the Chinese know it some time and the Europeans are acknowledging it right now: the US era/dollar is over.

Where to seek safe haven?

I think we cannot have a clear idea about what could possibly happen to gold/silver and the PM-shares, because there is no precedent to the situation we are facing today. Never in the past has a market equilibrium be postponed (in this case by derivatives) to the extent we are witnessing today.