Practically speaking I think it requires a lot of will, momentum, and process to change this. The decision even if made soon would probably take a few years to complete.

Supplementing it may be faster (eg. adding Euro and/or Yuan) than outright replacing it, but it’s not my area of expertise. The timeframe was based on some light research.

something to remember is that a good chunk of the "dollar" reserve is in reality eurodollars

the backing of which could be switched very quickly indeed

This stuff moves slowly, until it doesn't. I'd honestly say at least ten years for large changes.

And this will inflate away the debts tokenized in CCP-held US Treasuries. 4D chess! Russia did something similar in 1998 that sank the US hedge fund Long Term Capital Management.