I struggled to get through that financial engineering brain rot without feeling like I was damaging my intelligence. As far as I can tell in my super quick skim, it basically advocates for various forms of basically financial expropriation or freezing of Chinese assets and/or getting rid of the China held US Treasuries issue by simply either repudiating the debt or inflating it/paying it back with newly created money. Any of those actions would spell financial suicide for the US financial system and would destroy any remaining trust by other countries. It would lead to massively increased inflation, crash the bond markets and stock markets. It claims that China's leverage over the US is limited because any rapid sale of US Treasuries would result in financial loss and cause a spike in the RMB's value.
The other basic premise as far as I could tell was claiming that China is really weaker than it is because of the usual bogeymen of demographics, real estate doldrums, unemployment, as well as claiming that China's leverage is limited by time due to rest of world building up rare earths supply chain.
Sure, all of these actions could cause China pain but the devastation it would have on the current US led worldwide financial system would be greater, and at the end of the day China can produce the concrete material goods that actually make a difference to ordinary people's lives.
I have also wondered at this belief that somehow China wouldn't do something just because it would result in financial loss or upward spike in RMB. First, it betrays the over-fiancialization mindset of always looking at things purely in terms of monetary gain or loss rather than geopolitics. Second, couldn't China just readjust the RMB downward if desired by creating more RMB? That additional RMB could then be used to pay off debts of all sorts at all levels, from local government to national bonds.