i would love to see a working draw.io (
https://about.draw.io/) plugin for displaying and editing draw.io-graphs. unfortunately i'm not a good developer to build a own plugin :-/
it seems somebody started to build a plugin, downloadable via
https://github.com/upputter/diagram. but i guess it's too old and currently broken. with these extension it is possible to view a draw.io file in dokuwiki but the editor won't load and ends with a blank document.