[Paul R.]

Right. But, here I am not moving anything to a new platform.

It does occur to me that I did not try to copy / paste any individual files from C: (the eMMC “OS” drive) to D: (the new SSD). (My tests on “D” were copying a few files onto it from a USB stick, and then opening them, then deleting the copies.) But, in the past I’ve moved files from C: to a micro SD card I’d put in the laptop’s micro SD port semi-permanently for data storage, with no problems, and ditto for files transferred to a USB flash drive in any of the USB drive ports.

[Myrddin]

Using a read/write operation from the booted OS will skirt the encryption issues as files are decrypted on read from the source drive. If the target drive is not encrypted, you get decrypted copies on the target drive that remain unencrypted. Most cloning software does a low level block copy of file contents. It doesn't pass through a decrypting/decompressing OS layer.