China's foreign reserves are in excess of US$ 3 trillion, over half in US dollars. What happens if they start dumping them?

https://en.wikipedia.org/wiki/Foreign-exchange_reserves_of_China

https://tradingeconomics.com/china/foreign-exchange-reserves

Obviously the US$ crashes but that would effectively have the same result as tariffs - much higher prices for US imports. Could China weather it and what would they gain from it?

With the foreign reserves they have and the ability to ignore an unhappy population, it's survivable.

What could they gain from damaging their export industry? They've long been trying to stimulate domestic demand and would really like to end the US$ as the reserve currency.

However given the current situation they may wait for the US to implode on its own.