I want to create an editable tree graph using Vega. What's the best way to do this?

So far, my approach is to create an overlay layer with inputs for nodes titles (Figure 1). I see the same approach being used in tools like Miro or Whimsical.

The way I do this is I grab vegaView, get nodes layout coordinates (vegaView.data('tree')) and draw my inputs overlay based on it.

Is there a better approach to do this? I'm new to Vega, and I don't know a lot of things about it. Perhaps, I could use triggers or event streams for this somehow. Although, from what I saw so far – Vega can only draw inputs outside of its main drawing area (those bound to signals).