I have used a similar approach before and it works great every time. Draw the dependency tree in OmniGraffle, color the blocked nodes red, completed nodes green, and available nodes yellow, then work the yellow tasks in order of descending uncertainty. It gives such a good holistic picture of the project and makes it really easy to sync up with others.
I just haven’t found a collaborative tool, that would make it easy for my whole team to collaborate on the dependency graph.
Have you tried Figma?