I had a quick look at demo and dependencies are here, which is, as you mention, good and rare.

I don't want to steal the thread (lets focus on Vikunja), but I currently use Obsidian and am trying to achieve DAG with creating taxonomies using some extra plugins like Dataview and Breadcrumbs. It's basically `markdown notes connected`, which allows lots of freedom in creating such taxonomies. It is still not easy to visualize it all the way I imagine it. I would really like to have it visualized after all, think seeing it all visualized (and even being able to work directly with it) helps a lot.

For me it is a big step from not-so-useful lists of tasks... simple lists of tasks are simply useless for me.