have you tried it? it works on local files.
logseq has whiteboards which are more freeform like paper. And logseq integrates well with emacs and org-mode in general. There is also a mind map plugin for it.
https://www.youtube.com/@SystemCrafters/playlists
You are welcome.
https://www.youtube.com/@SystemCrafters/playlists
You are welcome.
Love it!