I love this idea, but would want to self host it. There are many other canvas options out there I can use that offer it, and I can mimic the nesting via links in something like Obsidian.

My work is primarily market strategy and product ideation. I do this in obsidian. Generally have a top level canvas and linked documents.

All the usual obsidian goodies work as expected.

I do like this app though. Great tool for preparing presentations to explain things and probably also great whiteboarding tool (company uses figma for that and it is beyond annoying!).