There are plugins for UML, dot, etc., but I couldn’t find one that allows me to create system diagrams. Any pointers?
The ideal plugin would be something based on mxGraph (using its xml notation) because then it can be modified through draw.io (it seems that the github source code can even be used inside tiddlywiki: https://github.com/jgraph/drawio). If none exists, I might try to create one, but it’ll take me time as I’ve never created a plugin.