There was a similar topic, and Pascal mentioned
" you should be able to explode any block instance one level, select all the bits and
Block into a new block. Does that do it or am I missing the idea?"
I wonder if this is now possible to duplicate a block as a new one. Yes, blocks can be exploded and edited; then be made as a new block. However, if I already placed a block at many locations at various angles/rotation, it’s important to pick exactly the same base point. If it’s a complex mesh object, it’s sometimes impossible to pick the exactly same base point.
It will be so convenient to be able to save as a new block after editing/changing material of a block inside a block editor.