This note from the Cato Institute gives what I asked for, an easy to read explanation of what CBDC dystopia would look like.
So, on how my "wealth could be switched on or off at an instant" as per
@tecate this is what it says. The scenario is where every economic transaction is done by CBDC and the Government have sight of the personal data of every such transaction. There are no notes or coin and there is no private sector money or if there is the government has the same look through to the underlying CBDC transaction.
My country estates, my castle, my stables and horses and my Rolls Royce would be still safely in my hands - my wealth could not be switched off. But if the government took a dislike to me they could exclude me from the economy. I could not pay my electricity bills, I could not pay the stable lads or the chauffeur, I could not enter my horses in races, I could not buy fuel for my Roller. Heck, I couldn't even buy a packet of fags. So forget my Marie Antoinette impersonation I would be no better off than the "vast majority" for whom their "wealth", being entirely in money, could indeed be "switched on or off at an instant".
Though, if the powers that be were so inclined, I could today be substantially excluded from the economy and be left scrambling with notes and coins, but for sure an entirely CBDC based economy would make the "off switch" easier.
Of course, this dystopia is a long way removed from the BoE musings in the OP. They are very keen to prevent government having access to personal transactional data. They very much see CBDC as acting in tandem with private money and they are particularly insistent that notes and coin are retained. But it could be the thin edge of the wedge and who knows what a future government might do, but if you over worried about that you probably wouldn't even build motorways which would facilitate rapid deployment of some future hostile state enforcement agencies.
Anyway, I have moved CBDC onto the negative side of my assessment. I really don't see the point and I see some genuine risks (rather than the Orwellian ones). The risk of financial disintermediation is very real. Also, and here I am just thinking instinctively as I haven't a clue, the cybersecurity risk would seem much greater in a fully centralised system. What are the benefits? The BoE is right. Be prepared but don't be a trail blazer.
Update: after a sleepless night I now know how I can avoid this Orwellian nightmare. I will open barter accounts. For example my Head Lad can have the use and prize money from my top racehorse provided he pays all my bills.