Greetings, Werner.

You should read some of the text in 'Draft', Werner.
As I point out, I only save the .img long enough to make sure the Knoppix[n]
replacement is doing its thing.
You may, and I do, get rid of the .img when I'm confident it went ok.
I don't find it convenient to compress the .img, either, and may delete
this option in some upgrade.

I am not clear on your insistence on .img as a 'device'.
I thought the notion of unix was that everything might be thought of as a file.
Please be more explicit on why you make this distinction.
Otherwise this comes across as simply a cavil.