if they don't create inflation, the system collapses. If they manage to do so, it would require helicopter money, basic income, or confiscating gold again and paying everyone who owns gold higher than market rate.
only problem is, only people who own gold is central banks and ETFs, so that plan can't work because the money wouldn't circulate
Easy way to create inflation is just to reprice gold overnight at some massively increased rate. Don't need to confiscate it, just say it is now worth $7000 an ounce. All of a sudden, you will have your inflation as all things are repriced. The US acts as broker / dealer & buys / sells to keep stability.
Problem is that gold is sort of out of favor (tellingly though, the central banks are mostly still buying. Except for Canada). But if not all parties have gold it be very disruptive to the financial system and the paper gold market would be very problematic.