Yes.
Although not addressing my latest questions, I think this should be included somewhere in this thread.
"Driver fix for fake or counterfeit CH340 chips"
Did you ask because you were thinking of suggesting I use the Group Policy facility to prevent update?
But the return of stability that I reported in post #146 is thankfully holding so far. And that's even after accepting a WU today, which included a reboot. So I'm reluctant to risk rocking the boat. I note that whatever is so far preventing the CH340 driver updating from 2019 (3.5.2019.1) to 2033 (3.8.2023.2) it can't be GPC, which reports no such exclusions.
Any thoughts about the "remaining worry" described in that same post? Or am I mistaken about a possible problem if I connect a Nano that needs the current (2033) driver?
Yes, if you have Pro you may be able to use Group Policy to prevent the updates. I found a discussion detailing that process. But it uses a different "Prevent" line than the one you highlighted.
https://superuser.com/questions/901803/prevent-windows-10-from-installing-updating-a-specific-driver
Edit: I don't think GPE should be necessary. I restored a previous version of my Intel Bluetooth driver recently, claiming that my apps don't work with the new one, and that has held through multiple reboots and updates. But to be fair, the update that didn't work was a Lenovo update, not a WU update. It's just that we don't know exactly what it takes to make Windows leave it alone. I think GPE would be a final option if nothing else works.
I just don't know. I don't know what's different about the 2023 version. If it was just adding some new CH models, it's unlikely that would ever cause a problem for a Nano. But we know it does a bit more than that. So I don't know.
@ShermanP ever heard of (or remember) FTDI gate? Something similar might be happening with the CH340.
I don't have a 'good' nano to try it. Do you or @sterretje ?
By 'good' I mean a clone with a clearly labeled CH340 chip. Of course not a genuine nano, which should automatically use an FTDI driver.
No, I don't have a "good" Nano. I thought mine were, but looking at them again I saw that they have no markings on the CH340 chips.
One thing I don't understand is why my Win10 machine doesn't try to update to the 2023 driver, or even the 2022 driver. It has stopped at 2019 for some reason. Not that I'm complaining.... 
I do have "good" Nanos but I'm not running Windows at the moment.
A post was split to a new topic: Where can I find out which error means what?
Back in the Windows game. I did install the driver linked in Port monitor error: command 'open' failed: Invalid serial port. Could not connect to COM serial port - #49 by ptillisch.
I did the installation without any CH340 devices connected. After that I connected a Nano and it worked; this was two days ago.
I did get some Windows updates coming along and tried an upload again just now and it is still working.
Win11 home.