Add COPY/PASTE to clipboard to all data blocks that can be appended

As you know we can append data blocks from one .blend file to another.

But there are already several data blocks, that can be just copied to the clipboard and pasted into the same or better: another open .blend file.

It's very handy, if you can copy a mesh from one .blend file to another e.g. The mesh includes all assigned modifiers in the target .blend file.

My wish: Please support "Copy->Paste to clipboard" to all data blocks that can be appended.

Example: I tried to copy a node from the compositor from one .blend file to another .blend file. This is not working yet (v2.81). I know I can make a group, save it and append it, but sometimes it's important to copy just one or more nodes without grouping them.

This would be very handy for copying Collections between .blend files, too.

I hope it will be possible sometime. It would help a lot.