As far as I can see, block-copied text just sits on the clipboard as plain text with \n at the end of each line.
Nope. As explained here
[#40 (comment)](https://github.com/geany/geany-osx/issues/40#issuecomment-1267472339)
the block-copied text also needs to contain the information it was block-copied in the clipboard, otherwise pasting might not work correctly in all situations.
I don't think a special clipboard format should be required, just that Geany can be put into a block-paste mode the same as using <shift-ctrl> puts it into block-copy mode. The benefit of this is that I can go to Notepad and copy out my shopping list in plain text and then paste it as a block elsewhere. If I wanted to.