I've never made one of these so I have no idea what all the issues are but I feel like I want it to act like presentation software. I want to be able to connect boxes with lines/arrows, then drag the boxes and have the lines stay connected to the boxes. I probably also want group things like I can in most structured drawing programs. Maybe that doesn't work well with ASCII
Like a simple example, I expect if have a object selected and press Cmd/Ctrl-C, Cmd/Ctrl-V I get a duplicate.
These interactions seem like basic table stakes