In simpler words: another US-domiciled lever that can be switched to the off position.
Huawei's CFO is currently on "house arrest" in a $10 million dollar estate in one of Vancouver's best neighborhoods, but free to move about the city so long as she's accompanied by a minder. As contrasted with the Canadians that China has kidnapped in retaliation and remain in secret prisons 8 months later with limited consular services. [1]
She's under arrest for wire fraud because to be extradited from Canada you have to have committed what would be a crime in Canada, and violating US sanctions is not a crime in Canada. She is not awaiting extradition, the trial hasn't happened yet, and she may well not be extradited if this is in fact primarily case of US extraterritoriality. One of her best arguments, per usual, is Trump's comments on the whole situation.
[1] https://www.bloomberg.com/news/articles/2019-05-08/huawei-cf...
I guess main problem is that to a very good approximation nobody wants these. Generally, the ones understanding monetary policy don't understand the need for privacy and the ones understanding need for privacy don't understand the need for negative rates and the rest don't care.
So what you want is... cash. But cash from a separate currency. This is identical to what we had here in Brazil in the 90s during the Plano Real transition: the cash everyone had was in the Cruzeiro Real currency, but all the prices were denominate in URV (a "virtual" currency, which months later became a real currency called Real). The Cruzeiro Real was suffering from inflation at the time, but the URV was stable, so to buy something with a price of 1 URV you might pay CR$ 864,14 one week and CR$ 1004,68 the next week (source for these values: https://pt.wikipedia.org/wiki/Unidade_real_de_valor).
This is a feature not a bug.